Gasteropoda. JIOLLUSCA.- Volutid.e. 



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 Mitres, 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." 



Fasiilt— TURBINELLID.E. 



The lamily of CHAUK or Turnip Shells, as they 

 are sometimes called [Turbinellidw), 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. 



Gexds TuRBrsELLDS. — 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 ( Turhinelhis 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 

 ex])ort 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 already 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. 

 Vol. II. 



In the Asiatic Journal for 1827, it was mentioned as 

 having then produced only 41,100 rix-dollars. The 

 Chank is used by the natives as an ornament. " It is 

 sawed into rings," says Bertolacci, " of diflerent 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 sliells 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 persons iii 

 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^. 



Tlie family of VOLUTES (Volutida:) 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 hack 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 

 great 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 

 speciiiicns. The species are numerous, and are equa- 

 torial in their geographical distribution. About ninety 

 recent species have been desciibed, 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 distu- 

 butiou. The animals of some of them have been 

 discovered to be viviparous. These form a group which 

 belong to the curious genus Yetiis 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, 



2 T 



