| 
                                    Ahnfeltia plicata (Huds.) Fr.
                                 | 
                                J. Butler 1251 | 
                                14 Jul 1938 | 
                                France | 
                                Bretagne | 
                                Côtes-d'Armor (Dept.). Côtes-du-Nord, Le Guen,… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Apopellia endiviifolia (Dicks.) Nebel & D.Quandt
                                 | 
                                J. Butler 750 | 
                                Jan 1932 | 
                                France | 
                                Normandie | 
                                Eure (Dept.). Bords de l'Epte… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Ascophyllum nodosum (L.) Le Jol.
                                 | 
                                J. Butler 877 | 
                                20 Jul 1931 | 
                                France | 
                                Bretagne | 
                                Morbihan (Dept.). Locmariaker | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Asperococcus bullosus J.V.Lamour.
                                 | 
                                J. Butler 1304 | 
                                24 Jul 1938 | 
                                France | 
                                — | 
                                Ploubazlanec, Baie de Launay | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Callithamnion corymbosum (Sm.) Lyngb.
                                 | 
                                J. Butler 1252 | 
                                24 Jul 1935 | 
                                France | 
                                Normandie | 
                                Manche (Dept.). Carteret | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Ceramium rubrum C.Agardh
                                 | 
                                J. Butler 1248 | 
                                10 Aug 1937 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Varengeville | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Ceramium rubrum C.Agardh
                                 | 
                                J. Butler 1248 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Ceramium rubrum C.Agardh
                                 | 
                                J. Butler 1248 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Chara globularis Thuill.
                                 | 
                                J. Butler 1169 | 
                                25 Jun 1936 | 
                                France | 
                                Nouvelle-Aquitaine | 
                                Landes (Dept.). Lac de Biscarosse | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Chondria dasyphylla (Woodw.) C.Agardh
                                 | 
                                J. Butler 1011 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Chondrus crispus Stackh.
                                 | 
                                J. Butler 1014 | 
                                10 Jul 1934 | 
                                France | 
                                Bretagne | 
                                Finistère (Dept.). Le Pouldu | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Chondrus crispus Stackh.
                                 | 
                                J. Butler 1014 | 
                                02 Aug 1938 | 
                                France | 
                                Bretagne | 
                                Finistère (Dept.). Kerhoulaouen | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Chorda tomentosa Lyngb.
                                 | 
                                J. Butler 1033 | 
                                10 Jul 1934 | 
                                France | 
                                Bretagne | 
                                Finistère (Dept.). Le Pouldu | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Cladophora refracta Kütz.
                                 | 
                                J. Butler 1238 bis | 
                                02 Aug 1938 | 
                                France | 
                                Bretagne | 
                                Finistère (Dept.). Kerhoulaouen | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Cladophora refracta Kütz.
                                 | 
                                J. Butler 1238 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Cladophora rupestris (L.) Kütz.
                                 | 
                                J. Butler 1237 | 
                                12 Jul 1934 | 
                                France | 
                                Bretagne | 
                                Morbihan (Dept.). | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Codium bursa (Olivi) C.Agardh
                                 | 
                                J. Butler 1303 | 
                                21 Jul 1938 | 
                                France | 
                                — | 
                                Ploubazlanec, Baie de Launay | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Codium tomentosum Stackh.
                                 | 
                                J. Butler 1241 | 
                                18 Jul 1934 | 
                                France | 
                                Bretagne | 
                                Morbihan (Dept.). | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Colpomenia sinuosa (Mertens ex Roth) Derbès & Solier
                                 | 
                                J. Butler 1010 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Colpomenia sinuosa (Mertens ex Roth) Derbès & Solier
                                 | 
                                J. Butler 1010 bis | 
                                15 Jul 1938 | 
                                France | 
                                Bretagne | 
                                Côtes-d'Armor (Dept.). Côtes-du-Nord, Le Guen,… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Corallina officinalis L.
                                 | 
                                J. Butler 1019 | 
                                25 May 1934 | 
                                France | 
                                Normandie | 
                                Seine-Maritime (Dept.). Antifer | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Cystoclonium purpurascens (Huds.) Kütz.
                                 | 
                                J. Butler 1409 | 
                                14 Jul 1938 | 
                                France | 
                                Bretagne | 
                                Côtes-d'Armor (Dept.). Côtes-du-Nord, Le Guen,… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Cystoseira fibrosa (Huds.) C.Agardh
                                 | 
                                J. Butler 1290 | 
                                15 Jul 1938 | 
                                France | 
                                Bretagne | 
                                Côtes-d'Armor (Dept.). Côtes-du-Nord, Le Guen,… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Dasya coccinea (Huds.) Aresch.
                                 | 
                                J. Butler 1134 | 
                                25 Jul 1935 or 26 Jul 1935 | 
                                France | 
                                Normandie | 
                                Manche (Dept.). Carteret | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Delesseria sanguinea (Huds.) J.V.Lamour.
                                 | 
                                J. Butler 955 | 
                                20 Jul 1934 | 
                                France | 
                                Bretagne | 
                                Morbihan (Dept.). | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 |