322 Gasteropoda. MOLLUSCA. Pkoboscidifeka. 
of the family, is of a cream-white colour, very hand- 
operculum, which varies considerably, and forms a good 
somely marked with rows of brown spots. The Spotted 
character for separating the species into groups or sub- 
Auger is from six to eight inches long, and of an 
genera. The shell is fusiform, with a turriculated spire, 
elegant shape. It is a native of the southern seas and 
more or leas elongate, with roundish whirls, and the 
the Indian ocean. 
aperture, which is ovate, terminates in a more or less 
elongate, straight canal. The Pleiirotomse are carni- 
Family III.— PLEUEOTOMID^ (Slit-mouths). 
vorous in their habits, and the family contains many 
species, which are world-wide, extending from Green- 
The family of Slit-mouths or Pleueotomas 
land to Australia, and from low water to one hundred 
(Pleurotomidce), have somewhat nearer relations with 
fathoms. None of the species are of great size, the 
the Cones than tlie Auger-shells. The teeth are simple. 
largest scarcely exceeding four or five inches in length. 
elongate and rather enlarged at the base, and the outer 
THE TOWER OP BABEL (Pleurotoma Bahylonica), 
lip of the shell has a notch or slit at or near its upper 
a native of the Indian seas and the Moluccas, is the 
extremity. The siphon is produced, and the mantle 
typical species of the genus. It is from three to four 
has a slit in the hinder part of the outer side, corre- 
inches in length, turriculated, with convex whirls ; is 
spending with the notch or slit in the lip of the shell. 
of a white colour, with circular keels or ridges which 
The foot is oval, short, thin on its edges, and carries on 
are sjjotted transversely with black square dots. The 
its posterior extremity a pretty thick, horny, annular 
canal is rather long. 
Sub-order IL— PEOBOSCIDIFEEA. 
This sub order contains a much larger number of 
the eyes are sessile, generally on the outer side near 
species than the preceding, and many exceedingly 
the base of these tentacles, though sometimes they are 
interesting and valuable shells are found amongst them. 
placed at the tip or behind them. The animals are 
The animals are carnivorous, feeding upon living mol- 
unisexual, and the females are generally much larger. 
lusca and other animals, and they are often found boring 
and have much more ventricose whirls to their shells. 
round holes in shells to arrive at their inhabitants. 
than the males. The eggs are contained in a kind 
“ Many wage war on their own relatives, and take 
of horny or leathery (coriaceous) cases, each holding 
them by assault ; the bivalve may close, and the oper- 
many eggs, but only a few of which ever come to 
ciliated nerite retire into his home, but the enemy with , 
perfection. “ The cases of Buccinum undatum (our 
rasp-like tongue, armed with silicioiis teeth, files a hole 
common wliilk) and Fusus despectus have been mis- 
through the shell — vain shield where instinct guides 
taken for the eggs of the oyster, and called Oystersput. 
the attack ! Of the myriads of small shells which the 
This error is the more remarkable as oysters are ovovi- 
sea heaps up in every sheltered ‘ ness,’ a large pro- 
viparous, the young being found in the branchiae of the 
portion will be found thus bored by the whilks or 
parent in the month of July ; the eggs of Purpura and 
purples ; and in fossil shell-beds, such as that in the 
other genera have, by a similar error, been described 
Touraine, nearly half the bivalves and sea-snails are 
as a species of Tuhularia." — (Gray.) The lingual 
perforated, the relics of Antediluvian banquets.” — 
ribbon of these animals is placed near the apex of 
( Woodward.) At page 1 84, we have described the teeth 
the exserted proboscis, and the teeth are arranged in 
of the gasteropodous mollusca, and have mentioned 
one, three, or seven rows ; the gills are placed in two 
there, that they are silicious in their composition ; and 
series along with some mucous filaments. The oper- 
being placed in the Proboscidifera or carnivorous species 
culum, when present, is horny and annular. The 
in several rows on a lingual ribbon, which is muscular 
shells of the different species are subject to great 
in its structure, we can easily conceive what powerful 
variation, according to the roughness or smoothness 
weapons they prove in penetrating the hardest shells 
of the sea they live in, and the quantity or quality of 
or coverings of their pre^L As animals which live on 
their food. Some of the common whilks (Buccinum 
animal food require the blood to be more perfectly 
undatum), for instance, are thick and rugose, others are 
aerated than those which feed upon vegetables, so in 
very thin, even, and finely coloured. These have been 
the Proboscidifera we find that they are provided with 
described as distinct species. Examples may be seen 
a siphon attached to the inner side of the front part of the 
in the fine collection of shells in the British Museum. 
mantle, which enables the water more freely to arrive 
We will now, taking that magnificent collection as 
at their breathing organs; and the shells are always 
our guide, proceed to mention some of the more 
formed with a canal placed in front of the pillar in 
important families of this sub-order. 
order to protect this siphon from injury. The proboscis 
is long, and being furnished with a number of muscles. 
Family I. — CASSIDULIDAl (Fig-shells). 
can be exserted a great way from the head, and with- 
drawn again like the horns of a snail, so as to be hidden 
The family of Fig-shells (genus Pyrula of Lamarck ; 
within the body — see fig. 52, proboscis of Buccinum. 
family Cassidulidee of Gray) are the first in order. As 
The tentacles are placed close together at the base of 
constituted by the celebrated Lamarck, the genus 
the proboscis, or are united by a veil at that part ; and 
Pyrula contains several types dissimilar amongst them- 
