Gasteropoda. M OLLU SC A. V olutid Ai. 329 
especially to be the case with the Bishop’s Mitre {M. 
episcopalis) which has a small foot and a heavy shell, 
and is decidedly a sluggish creature. This, however, 
is not the case with the smaller, longitudinally ribbed 
species. According to Mr. A. Adams, who during the 
voyage of H.M. ship the Samarang, had good oppor- 
tunities of watching these animals among the Philippines 
and in the China sea, they crawl about pretty briskly 
over the smooth sand on the low coral islands. Some 
of them, he says, have the art to cover themselves all 
over with the sandy mud in which they dwell, and in 
that disguised condition travel about in comparative 
security. “On one occasion,” he remarks, “in the 
small island of Ambolan, at the south end of Mindoro, 
I was walking up to my ankles in water, over a firm, 
sandy, mud flat, taking little notice of the Cones, 
Strombi, Meleagrinae, and Volutes, which people the 
water in great numbers, but looking anxiously about 
for the rare Miti-es, when I first perceived these small 
species, under their ingenious disguise, marching in 
towards the shore, as the tide flowed rapidly over the 
level surface.” 
Family— TURBINELLID^. 
The family of CHANK or Turnip Shells, as they 
are sometimes called [Turbinellida), are ovate, fusiform, 
or top-shaped, thick, with a large body, a conical spire, 
and an elongated, straight canal, with several transverse 
folds on the columella near its middle. The operculum 
is ovate, claw-shaped. The species are rather numer- 
ous, nearly sixty having been described, as inhabiting 
chiefly the warmer seas of the West Indies, South and 
West America, Africa, Ceylon, the Philippines, and the 
Pacific. 
Genus Turbinellus. — The species of this genus 
have a thick, obconic, smooth, or somewhat waved 
shell, with an obtuse, mamillated spire, and its mouth 
ovate and narrowed in front. In none of the species 
have the animals as yet been scientifically examined, 
but the operculum has the inner edge straight. 
THE CHANK-SHELL {Turbinellus pyrum) is an object 
of sacred regard in Ceylon and the opposite coast of 
India, and the reversed varieties of it are used by the 
priests for administering medicine with. They are 
carefully and elaborately carved by the Cingalese, who 
find it an article of considerable commerce. The 
fishery of these shells has been frequently mentioned 
by authors and travellers, Bertolacci, in his “ account 
of Ceylon,” gives some very interesting particulars. 
The Chank fishery is an object of material consequence, 
he says, to the British Ceylon government, in point of 
revenue. This, till the year 1813, was derived in two 
ways; first, by the sale, or farming of the exclusive 
privilege of fishing this shell, and secondly, by the 
export duties upon Chanks when taken from Ceylon, 
which average 5000 rix-dollars a year ; the duty being 
an ad valorem one of five per cent. When Ceylon was 
taken by the British in 1795, the Chank farm of 1795-96 
had alreadj' been disposed of by the Dutch for 19,850 
rix-dollars. The English government let the farm for 
1796—97 for 22,250 rix-dollars, and from that date to 
1811—12, it varied from this sum to 64,468 rix-dollars. 
Von. II. 9!i 
In the Asiatic Journal for 1827, it was mentioned as 
having then produced only 41,100 rix-dollars. The 
Chank is used by tbe natives as an ornament. “ It is 
sawed into rings,” says Bertolacci, “ of diiferent sizes, 
and worn by all Indian women as an ornament, on 
their arms, legs, toes, and fingers. But the great 
market for the sale of these shells is Bengal, where a 
religious prejudice is entertained in their favour; in 
consequence of which, thousands of them are buried 
with the bodies of opulent and distinguished pei'sons in 
that part of India; this is the cause for the great and 
constant demand for them.” “ But this fishery,” adds 
the same writer, “ is of even greater importance ; 
because it is a great nursery for divers, whose services 
are wanted in the pearl fishery.” 
Family— VOLUTID.®, 
The family of VOLUTES ( Volutidcc) comprises the 
True Volutes and the Date shells. The mantle is 
provided with a siphon which is very short and 
recurved, and the shells are channeled in front for its 
reception. The columella in all is plaited with from 
two to five or more distinct folds ; the operculum, is 
only present in some of the sub-genera ; it is horny and 
annular. In the True Volutes the animals have a 
large foot extending beyond the shell in all directions, 
and deeply nicked on each side in front. In general 
the shell is covered with a distinct epidermis, but in 
one or two species one of the sides of the mantle is 
produced and reflected over the back of the shell, 
covering that portion of it, as well as the spire, with its 
shelly secretion, and producing a polished surface like 
that of the Olives and Cowries. Amongst the Volutes 
we find a number of large shells, remarkable for their 
gi'eat beauty and the elegance of their forms. The 
family is, therefore, of course very much sought after 
by collectors, and large prices are often given for single 
specin;ens. The species are numerous, and are equa- 
torial in their geographical distribution. About ninety 
recent species have been described, a large proportion 
of which (sixty-four) are from the Australian seas, the 
rest being distributed through the seas of the West 
Indies, and the west coast of America, the great 
Eastern Ocean from Java to Japan, and the coasts of 
Africa. In consequence of the number of species, and 
the remarkable variety in form amongst them, several 
genera have been constituted to facilitate their distri- 
bution. The animals of some of them have been 
discovered to be viviparous. These form a group which 
belong to the curious genus Yekis so well observed by 
the celebrated Adanson in Senegal. 
Genus Yetus. — The shell of Yetus is ventricose, 
spire short, and mouth expanded. The surface is 
covered with a horny sort of epidermis, but the mantle 
is so large and so expanded that it extends over a great 
portion of the shell and covers this epidermis with a 
glassy coat of enamel. We frequently see the surface 
studded over with little roughnesses or points. This 
arises from particles of sand getting between the shell 
and the upper surface of the foot, when these extraneous 
bodies become covered with this polished layer of glassy 
secretion in order to prevent them irritating the animal. 
