THE GASTROPODA 149 
Genera — Emarginula, Lamarck; anterior border of the mantle 
and shell with a slit; British seas. Rimula, Defrance. Subemarginula, 
Blainville. Scutwm, 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. Fisswrella, Bruguitre ; 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, VOrbigny. Pupillia, Gray; mantle completely covering 
the shell. Lucapina, Gray. Megatebennus, Pilsbry. | Macrochisma, 
Swainson.  Lucapinella, Pilsbry. Faminy 7. Coccuninipar, Dall. 
Shell conical, symmetrical, without slit or perforation; the summit 
inclined backwards. Genus — Cocculina, Dall; dioecious; abyssal. 
Famity 8. Trocaipar, d’Orbigny. Visceral mass and shell spirally 
eas 
pa 
XI 
Vu 
Fic. 130. 
Trochus (Gibbula) cinerarius, right-side view. I, shell; II, frontal lobes ; III, right eye and 
pedunele ; IV, right tentacle ; V, appendage of the right ocular peduncle ; VI, snout; VII, right 
epipodial lobe; VIII, epipodium ; LX, 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—Tochus, 
Linnaeus ; no jaws; shell umbilicated ; spire pointed and prominent. 
Monodonta, Lamarck ; no jaws; spire not prominent; no umbilicus ; 
columella toothed. Olanculus, Montfort. Elenchus, Swainson. Photinula, 
Adams. Gaza, Watson. Gibbula, Risso; 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. Faminy 10. DELPHINULIDAE, 
Fischer, Visceral mass and shell spirally coiled ; operculum horny ; in- 
