FRONT-GILLED GROUP 3345 



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 seetn 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 forms. Mitra sonata, 

 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 Mitrida 

 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 of 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 two feet. In Leucozonia, 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. dngulata 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 eighteen 

 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 

 of Turbinellidce, the shells are compact and very strong, tuberculous or spiny, 

 with short spires, and the anterior canal considerably shorter than in Turbinella. 

 The aperture is armed with a few folds on the middle of the columella, and is closed 

 by a thick and somewhat twisted operculum. The eight known species are dis- 

 tributed over the Red Sea, Philippine islands, Polynesia, Pacific coast of Central 

 America, and the West Indies. Fulgur and Melongena both include large striking 

 shells from the United States and West Indies; and Sycotypus canaliculatus , also 

 from the States, is remarkable for the deeply channeled suture separating the 

 whorls. The egg capsules are very curious, consisting of a long string of round 

 discs, about the size of a shilling, but somewhat thicker, attached to the cord by 

 one edge. Each capsule contains a number of eggs, and the young eat their way 

 out at a spot opposite the points of .attachment. Semifusus colosseus is one of the 



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