mamimiform spire, and the unsymmetrical finish, or more correctly commencement 
of the suture, give the shell an awkward appearance. The whelk requires two or 
three seasons to attain maturity, and certainly lives six yeajs, probably more, for 
I have obtained, from the deep water outside the Dogger-bank off Scarborough, 
full-grown living specimens of the large variety " pelagica " with four-year-old 
oysters attached to the last or largest volution. 
The arrangement of the sexes in the mollusca is very interesting. The terres- 
trial gasteropoda (such as the garden snail) are monoecious, each individual 
possessing both sexes, yet incapable of self-fertilization. Some of the fresh-water 
gasteropoda, as " Valvafa," change their sex, first being male and afterwards fe- 
male, and are capable of self-fertilization ; whilst the whelk, and probably all 
marine gasteropoda, are dioecious, each individual being of one distinct and 
unalterable sex. The male whelk has a longer and slenderer shell than the fe- 
male j the sex, however, cannot be determined by the shell. 
The proboscis of the whelk is singular and interesting. It is a long conical and 
retractile member, which can be protruded two or more inches beyond the snout, 
or retracted into a chamber which is situated on the upper part or back of the 
animal. The length of the chamber is not one-half that of the proboscis it 
receives. At its base the proboscis is attached to the anterior part of the chamber^ 
from the sides and posterior part ot which a number of muscular fibres radiate, 
having the other extremities attached to the inside of the proboscis. The contrac- 
tion of these fibres draws the anterior part of the proboscis within the posterior 
part, in very much the same manner that a stocking is doubled back upon itself. 
By means of this highly ingenious piece of mechanism the space required for the 
reception of the proboscis is reduced one-half. Within this muscular sheath or 
proboscis is the lingual ribbon or tongue, which has lately received the name of 
"odontophore." Upon it, most beautifully and regularly arranged, are numerous 
hard and pointed teeth, and, like all the odontophores of the gasteropoda, it is a 
very interesting object for microscopical investigation. Some systematists assert 
that the odontophore affords sure evidence of, not only specific and generic, but 
also of family distinctions. Professor Stimpson has lately raised Nassa from being 
a genus in the Buccinidse to the type of a distinct family, which he calls Nassidae 
(which includes the genus Columbella), solely on odontologial grounds, namely, 
«' the arched form and very numerous denticles of the rachidian tooth." 
B. — Geological development. Buccinum undatum first made its appearance 
during the epoch of the Coralline Crag, and is therefore geologically speaking a 
creature of yesterday. Since that epoch down to the present time it has become 
more and more abundant, and is now one of our commonest shells, living in 
countless millions in all our seas. 
2nd— Its Habits. The whelk is a carnivorous predatory creature. Crawling 
over the sea bottom in search of dead fish or mollusca, it performs the duties of 
a scavenger. Having found a living mollusk (it seems to p refer a bivalve) it 
seizes it with its ample foot and by a semi-rotatory motion of the proboscis, in 
which is the armed tongue previously described, it drills a hole through the shell, 
killing and afterwards devouring the inhabitant. The length of time occupied 
in doing this of course depends entirely on the thickness of the shell operated 
