40 
NATURAL HISTORY. 
[EAST. ZOOL. 
Table 18. The apple snails (Ampullaria). The reversed apple 
snails ( Lanistes ). The purple, or floating snail ( lanthina ). 
Table 19. The nipple shell (Natica). The Venus’ ear ( Crypto¬ 
stoma ). The winkle ( Littorina ), and other genera allied to them. 
The pagoda shell ( Pagodus ). The staircase shell (Solarium), so 
called on account of the ridge round the cavity in the axis or 
umbilicus resembling a well staircase. 
Table 20. The Fresh-water Clubs (Melania) ; the clubs ( Cerithium )* 
Table 21. The screw (Turritella), as the press screw ( T. bicari- 
nata). The milk shell (Eulima). The ladder shell (Scalaria), often 
called by the Dutch name, Wentletrap, signifying a winding ladder; 
they were formerly very rare, but are now brought from China. The 
pond snails (Paludina). The worm shell ( Vermetus), which is like 
the tubes of serpulse. 
Table 22. The fool’s cap ( Capulus), and the Hipponyx with its 
shelly under valve, which has caused it to be mistaken for a bivalve 
shell. The slipper shell ( Crepidula). The cup and saucer limpet 
(Dispotea). The Trochus-like limpet ( Trochita) and the Neptune’s 
cap, which has a cup-shaped under valve. The carrier (Phorys), 
which has the peculiarity of attaching to the outer surface of its 
shell, as it enlarges in size, stones, fragments of other shells, coral, and 
other marine substances, from whence it has been called respec¬ 
tively the “ Conchologist,” and the “ Mineralogist,” as shell or mineral 
preponderated. Some of the species have this habit only in an early 
stage, others retain it during the whole period of their existence; 
some have the margin of the whorls expanded into a broad disk, 
others have this part furnished with a series of long tubular processes 
like the rays of the sun, hence the name of Sun Carriers. The false 
limpets (Lottia); tooth shell (Dentalium). The Bubble Shells (Bulla), 
and the shelly plates found in the gizzard of some of the species. The 
rose-bud (Bullina). 
Tables 23,24. The horny shells found under the skin of the sea hares 
(Aplysia), and the shelly blade bone shell of Dolabella , from the In¬ 
dian seas. The very fragile and thin glassy nautilus ( Carinaria ), and 
the different species of paper nautilus or Argonauts. The poetic ac¬ 
count of the animal usually found in this shell using its dilated arms 
for sails, and its slender arms as oars, from whence Pope gave his well- 
known lines, 
“ Learn from the little Nautilus to sail, 
Spread the thin oar and catch the driving gale,” 
proves to be a fiction. The dilated arms are used by the animal to 
clasp the shell and keep it on the body, when it passes through the 
water, like other cuttle fish, with the broad part of the body forwards. 
The flat orbicular shell of the Chinese umbrella ( Umbrella), and the 
horny thin silvery shells found under the skin on the backs of Pleuro - 
branchus and Berthella. The Limpets (Patella). Scaly Chitons 
(Chitons). Spiny Chiton (Acanthopleura). Leathery Chiton ( To- 
nichia). Fasciculated Chiton (Acanthochetes). Chitonella, or sea 
caterpillars, and the Amiculce, or shelless chitons. 
Tables 24—30. The various genera of Land Shells, as the shelly 
