Order I.— FVLMONl A— (continued). 



Pupa, 35 

 Chondrus, 35 

 Succinea, 35 



Clausilia, 36 



Achatina, 36 



PiUmonea Aquatica. 



Oncliidium, 37 

 Planorbis, 37 

 Limnaeus, 38 

 Physa, 38 

 Scarabaeus, 38 

 Auricula, 39 

 Conovulus, 39 



Order II.— NUDIBRANCHIATA, 39 



Doris, 40 

 Onchidora, 40 



Plocamoceros, 40 | 



Polycera, 40 j 



Tritonia, 41 1 



Thetliys, 4 1 ' 



Scyllaea, 41 '■ 



Glaucus, 42 j 



Laniogerus, 42 



Eolidia, 42 '; 



Cavolina, 42 ' 



Flabellina, 43 \ 



Tergipes, 43 ' 



Busiris, 43 . 



Placobranchus, 43 



Order III.— INFEROBRANCHIATA, 43 



Phyllidia, 44 

 Diphyllidia, 44 



Order IV.— TECTIBRANCHIATA, 44 



Pleurobranchus, 44 



Pleurobranchsea, 45 



Aplysia, 45 



Dolabella, 46 



Notarchus, 46 



Bursatella, 47 



Akera, 47 



Bulljea, 47 

 Bulla, 48 



Akera jiropcr, 48 



Gastroptcron, 48 



Gastroplax, 49 



