SYNOPSIS OF THE FAMILIES. X1. 
Family—Turritellide.—Shell turreted ; eyes on the outer bases of the 
tentacles ; operculum multispiral - - 8: 
ss Vermetide.—Shell irregularly twisted ; mantle and shell with- 
out a longitudinal slit - S4 
Pe Siliquariide.—Shell irregularly tw Eeshipeti rantitle and eheul 
with a longitudinal slit - - Sd 
As Calyptride.—Shell depressed, with an al shelly flate - 8&6 
5p Capulide.—Shell conical, simple ; rostrum long - - 87 
AS Acmeade.—Shell, conical, simple ; rostrum short - = 188 
Division— ASPIDOBRANCHIATA.—Gills pectinate, upper wall of mantle 
cavity not prolonged into a siphon; dentition ripido- 
glossal ( .4-6,1.4- a a). 
Family—Weritide.—Shell spiral, not pearly within ; operculum articu- 
lated - - - 89 
3% Trochide. —Shell epinal pearly pichin ; animal with 3 to 5 
lateral filaments - - - - 90 
‘3 Haliotide.—Shell ear-shaped, perforated with a series of holes 104 
- Fissurellide.—Shell conical, pierced at the apex or grooved 
anteriorly - - - - - - 105 
Division—CycLoprancuiata.—Gills laminar, forming a more or less 
complete ring beneath the margin of the mantle. Shell 
of one valve only. 
Family—Patellide.—Shell, conical, simple - . - - 107 
Division—PotypLacoPpHora.—Gills laminar, one on each side of the 
hinder part of the body. Shell of several valves. 
Family Chitonide.—Shell ot eight valves, immersed in the mantle = - - 110 
Sub-order—OPiIstHoBRANCHIATA. —Gills behind the heart. 
Division—TECTIBRANCHIATA. —Gills protected by a fold of the mantle, 
and generally by a shell. 
Family Actwonide.—Shell external, solid - - - - 119 
* Aplustride.—Shell external ; eyes at inner bases of tentacular 
lobes® = 7 = - - - - = - 120 
iy Cylichnie.—Shell external ; eyes in front of the bases of the 
tentacular lobes - - - - - - 120 
a Buliide.—Shell external ; eyes none - - - = 11 
* Philinide.—Shell none or internal ; no tentacular lobes - 122 
6 Aplysiide.—Shell none or internal ; head with separate ear- 
like tentacles ; labial tentacles produced - - = lies} 
A Pleurobranchide Shell none, internal, or external ; head with 
ear-like tentacles ; mouth with an oral veil = SDA: 
Division—NUDIBRANCHIATA. —Gills exposed, or contractile into cavities 
in the mantle. 
Section—ANTHOBRANCHIATA.—Gills plumose, arranged round the 
anus. 
Family—Doridie.—Mantle large ; skin with spicules - - - 125 
Section—AIOLOBRANCHIATA.—Gills various, not arranged round the 
anus. 
Family— olidide. —Gills on the sides of the back . - - 129 
Class—Scaphopoda. 
Body worm like ; head rudimentary. 
Family— Dentaliide.—Shell elongate, the apex perforated - 130 
Class—Pteropoda. 
Pelagic ; two fin-like expansions anteriorly. 
Order—TueEcosomaTa.—Furnished with a shell. 
Family—Hyalide.—No posterior appendage between the fins - - 131 
