] 6 ZOOLOGICAL COLLECTIONS. [UPPER 
The Shells of Molluscous Animals are placed in the larger 
Table Cases across the sides of the room.^ 
Tables 1-20. The Gastropods, like the Whelk and Snail, which 
creep by means of a fleshy surface projecting from the under part of 
the body and called the foot, and have comb-like gills. Some of the 
more marked are the Cones, such as the rare " Glory of the Sea," from 
the Philippine Islands ; the animals of these kill their food by 
means of poisonous teeth implanted in their beak. Tables 3-13. The 
Trunk-bearing Mollusca, which, with the hard teeth in their long pro- 
boscis, make perforations in other shells and extract their contents ; 
the Olives, Harps, Persian Carpets, Turnip shells, Mitres, Volutes, and 
Date shells ; the Helmet shells, used in making artificial Cameos ; the 
Wentletrap or Staircase shells, once celebrated among collectors for 
their rarity. The Violet shells, which float on the ocean and, like the 
Murices, emit a purple fluid which has been used as a dye. Tables 
14-20. The Rostrum-bearing Mollusca, with a long muzzle with ten- 
tacles on the sides ; as the Apple Snails, which live in ponds in 
warm climates ; the Cowries — one kind is extensively used in place 
of small coin in Africa. These all crawl on a broad expanded foot. 
In Tables 19, 20 are the Strombs and Carrier-shells, which have a 
compressed foot for leaping. The Carrier-shell has the peculiarity 
of attaching to the outer surface, as it inc-reases in size, stones, frag- 
ments of other shells, coral and other marine substances, and has 
been called "the Conchologist " and "the Mineralogist," according as 
shells or minerals preponderated. 
Tables 21-25. The Scutibranchous Mollusca, the gills of which con- 
sist of lamellae, forming one or two series on the back of the neck or 
on the under edge of the mantle round the foot ; such as the Trochid«^ 
the Haliotidse or Earshells with their pearly lustre ; the Fissurellse or 
Keyhole limpets ; the Limpets with their simple conical shells, and the 
many-valved Chitons, which have a series of eight shelly pieces or 
" valves " down the back of the animal. 
Tables 25-30. The Heterobranchous Gastropods, with variously- 
formed respiratory organs. The Bullidse are placed here, with their 
curious strong gizzards ; the Bubble shells, the Aplysia or Sea Hare, 
which feeds on sea-weeds and discharges a deep purple fluid when 
danger approaches ; the Helicidse, or Snails and other allied families, 
which live on land and have cylindrical retractile tentacles. 
Tables 31-48. The Bivalve shells or Conchifera; the animal 
of these is enclosed between two shelly valves, united by a liga- 
ment. Tables 31-38 contain the Siphonophora, which have the 
mantle closed behind, and furnished with two apertures, the lower for 
the admission, and the upper for the emission, of the water from the 
mantle cavity. Some of these, as the Veneridse and other families, 
crawl on a compressed foot, while the Cockles have an elongated foot, 
angularly bent in the middle, and fitted for leaping. Near these, but 
with a small rudimentary byssiferous foot, are the Tridacnss, one of 
* Models of the animals of most of the families are arranged in the Cases 
along with the shells. 
