17 



145 anatina, L. — 25. 



b. radiata, Jeff. 



c. ventricosa, C. Pfr. 



d. complanata, Rossm. 



e. piscinalis, ' Nilss.\ Br. 



f. rostrata, ' Kok.\ Br. 



g. cristata, Nls. 



h. arelatensis, J acq. 



i. normandi, Dup. 



k. pictetiana, Movt. 



1. rayii, £)«/>. 



ni-. scaldiana, Dm/. 



n. milletii, ifa_y and Drouet 



DREISSENID^. 



Dreissena, Van. Ben. 



146 polymorpha, Pall. — 23. 



APPENDIX. 



(i)~ Species which formerly existed 

 in Britain, and still exist else- 

 where. 



147 Vitrina diaphana, Draft. 



147 Helix hispida, 



var. m. sinistra, hoc. 



148 Helix fruticum, Mull. 



149 Helix labyrinthica, Say. 



150 Patula ruderata, Stud. 



151 Hydrobia marginata, Mich. 



152 Corbicula fluminalis, Mull. 



153 Unio littoralis, Drp. 



(2) Estuarine or Marine 

 Pulmonobranchs. 



154 Oncidium celticum, Cuv. 



155 Assiminea grayana, Leach. 



156 Assiminea littorina, D.Ch. 

 b. albida, Sykes. 



157 Melampus bidentatus, 

 ' Mow*. 



b. albus, Turt. 



c. erosus, Jeff. 



158 Melampus myosotis, Dr/. 

 b. ringens, Turt. 



159 Otina otis, Turt. 

 b. Candida, Jeff. 



(3) Species erroneously quoted as 

 British. 



160 Helix villosa, Drp. 



161 Helix personata, Lam. 



162 Helix limbata, Drp. 



163 Clausilia parvula, Stud. 



164 Clausilia solida, Drp. 



