GASTROPODS. 



375 



The gorgeously-coloured mitre-shells (Mitridce) always have been and still remain 

 a favourite group with collectors. Like the Marginellas, they have no operculum, 

 and are small in comparison with the volutes, but they equal if not surpass them 

 in the beauty of their colour-markings and surface sculpture. The columellar lip 

 is always plaited, the hinder plaits being the strongest. A remarkable feature of 

 the genus, at all events in some instances, is the enormous length of the proboscis, 

 which seems to be out of all proportion to the animal. The tongue of the mitras 

 has three rows of teeth, all serrated in some species, but in others, with the two 

 laterals simple, and of a somewhat different type. The common Mitra episcopalis, 

 a striking, scarlet-spotted, heavy shell, is abundant at the Philippine Islands, and 

 occurs in Ceylon and in Polynesia. The animal is sluggish in its movements, and 

 buries itself in the sand when the tide recedes. The mitras with simple lateral teeth 

 are mostly ornamented with longitudinal ribs or plicae, and constitute the group 

 Twrris. Some frequent coral-reefs, and others are found, often in considerable 

 numbers, crawling upon the sands in sheltered and shallow bays. Over five hundred 

 species of Mitridce are known. They abound in the islands of the Indian and Pacific 

 Oceans, and seem to be scarcer on the shores of the great continents. They are 

 not very numerous in the Atlantic, and even the tropical islands of the West Indies 

 produce but an insignificant number, of unattractive form. Mitra zonata, found 

 in deepish water off" Italy and in a few other parts of the Mediterranean, is a 

 fine species, and one of the rarest of the family. A few species of Mitridce range as 

 far north as Japan, and others occur at the Cape of Good Hope and New Zealand. 



The tulip-shells, forming the family Fasciolariidce, are mostly fusiform (spindle- 

 shaped), some having very long spires and anterior canals. They never have a 

 thickened lip to the aperture, which is often grooved and striated within. The 

 typical genus Fasciolaria and also Latirus exhibit oblique folds on the columella, 

 a feature absent in the slender Fusus. All are furnished with a horny operculum. 

 The radula has three rows of serrated teeth, the central tooth being narrow, and 

 the laterals broad. Fasciolaria gigantea, from the coast of South Carolina, is one of 

 the largest gastropods, attaining a length of 2 feet. In Leucozcmia, a group of the 

 genus Latirus, the outer lip of the shell has a more or less prominent spine-like tooth 

 in front. In L. cingulata, from Panama, it is sometimes five-eighths of an inch in 

 length, and although it appears as if it would be a hindrance to the animal when 

 crawling, it doubtless serves some purpose in its economy. The allied family of 

 the chank-shells (Turbinellidce) is not numerous in species, but contains several 

 large and interesting forms. They are grouped together, on account of a similarity 

 in dentition. The radula has three rows of teeth, the central tooth being nearly 

 always three-pronged, and the laterals generally armed with a single or two 

 unequal cusps. The typical species of Turbinella have very solid, heavy, pear-shaped 

 shells, covered with a thick, fibrous periostracum, and exhibit a few strong oblique 

 folds on the columella. The T. scolymus, a West Indian form, is sometimes 18 

 inches long. In India, Turbinella is largely used in the manufacture of carved 

 bracelets, anklets, necklaces, and other ornaments. They are known under the 

 name of chank-shells, and a fishery is carried on in the Gulf of Manaar. Occa- 

 sionally sinistral examples are obtained, considered sacred by the Hindus, and also 

 valued by the Buddhist priests of Ceylon and China. In Cynodonta, another group 



