THE GASTROPODA 



149 



Genera Emarginula, Lamarck ; anterior border of the mantle 

 and shell with a slit ; British seas. Simula, Defrance. Subemarginula, 

 Blainville. Scutum, Montfort ; mantle split anteriorly and partially 

 reflected over the shell, which has no anterior slit. Zeidora, Adams. 

 Puncturella, Lowe ; mantle and shell with a foramen in front of the 

 summit of the visceral cone ; British. Fissurella, Bruguiere ; mantle 

 and shell perforated by a hole at the summit of the visceral cone, the 

 hole leading into the branchial chamber ; British. Glyphis, Carpenter. 

 Fissurellidea, d'Orbigny. Pupillia, Gray ; mantle completely covering 

 the shell. Lucapina, Gray. Megatebennus, Pilsbry. Macrochisma, 

 Swainson. Lucapinella, Pilsbry. FAMILY 7. COCCULINIDAE, Dall. 

 Shell conical, symmetrical, without slit or perforation ; the summit 

 inclined backwards. Genus Cocculina, Dall ; dioecious ; abyssal. 

 FAMILY 8. TROCHIDAE, d'Orbigny. Visceral mass and shell spirally 



XI 



FIG. 130. 



Trodius (Gibbula) cinerarius, right-side view. I, shell ; II, frontal lobes ; III, right eye and 

 peduncle ; IV, right tentacle ; V, appendage of the right ocular peduncle ; VI, snout ; VII, right 

 epipodial lobe ; VIII, epipodium ; IX, claviform appendage under the epipodial tentacle ; X, 

 posterior (operculigerous) part of the foot ; XI, epipodial tentacle. 



coiled ; a single ctenidium ; eyes open (Fig. 100) ; a horny operculum ; 

 flattened lobes between the tentacles (Fig. 130, II). Genera Trochus, 

 Linnaeus ; no jaws ; shell umbilicated ; spire pointed and prominent. 

 Monodonta, Lamarck ; no jaws ; spire not prominent ; no umbilicus ; 

 columella toothed. Clanculus, Montfort. Elenchus, Swainson. Photinula, 

 Adams. Gaza, Watson. Gibbula, Kisso ; with jaws ; three pairs of 

 epipodial cirrhi without pigment spots at their bases (Fig. 130) ; British. 

 Margarita, Leach; from five to seven pairs of epipodial tentacles with a 

 pigment spot at the base of each. Livona, Gray. Basilissa, Watson. 

 FAMILY 9. STOMATELLIDAE, Gray. Spire of the visceral mass and shell 

 much reduced ; a single ctenidium. Genera Stomatella, Lamarck ; 

 foot truncated posteriorly ; an operculum present ; no epipodial 

 tentacles. Gena, Gray ; foot elongated posteriorly ; no operculum ; 

 epipodial tentacles present. Stomatia, Helbling ; foot not truncated ; 

 operculum and epipodial tentacles absent. FAMILY 10. DELPHINULIDAE, 

 Fischer. Visceral mass and shell spirally coiled ; operculum horny ; in- 



