358 MARINE INVERTEBRATES 



extreme southern Florida. F. barbadensis has heavy longitudinal ribs and 

 is light green within, with a rosy circle about the apical perforation. 

 (Plate LXV.) 



GENUS Gli/phis 



G. aspersa. One of the numerous species belonging to this family 

 which are found on the west coast of the United States. It is about one 

 and a half inches long, grayish-white, with sharply raised longitudinal 

 ridges, slightly rayed, crossed by revolving ribs, which give to the 

 outer surface a decussated appearance. The apex is forward of the 

 center, and is entirely replaced by a round perforation. The edge is 

 wrinkled, and within smooth and white. 



GENUS Lucapina 



L. crenulata. The largest of the keyhole-limpets ; the shell is often 

 four inches in length, while the animal, with its huge yellowish foot and 

 dark-colored mantle, which is thrown back, almost concealing the shell 

 upon its back, is much larger. The apical perforation is very large. Shell 

 flattened, with radiating, rounded, crowded ribs ; brownish -white in 

 color ; edge crenulated ; within pure white. It is found at Monterey, but 

 live specimens are not very frequently seen near the beach. (Plate 

 LXVI.) 



FAMILY HALIOTIDJE 

 GENUS Haliotis 



This family is closely allied to the Fissurellidce. The species are 

 known on the Pacific coast by the name of abalone shells, and in 

 England and the Channel Islands as ormers or sea-ears. There 

 are no species of Haliotis on the east coast of the United States, 

 but one has recently been dredged at a considerable depth in West 

 Indian waters. This family, with the last, possesses the striking 

 anatomical feature of having the heart traversed by the digestive 

 tract. It also has two gills, the degree of torsion in the visceral 

 mass not being sufficient to have crowded out and destroyed the 

 original right gill. The shell is spiral, but is so greatly flattened, 

 and the body- whorl is so greatly extended, that the shell quite 

 loses the spiral appearance. Along the dorsal side of the shell is 

 a row of holes, through which project numerous tentacular pro- 

 cesses from the mantle. The outer surface of the shell, before it is 

 polished, is usually rough and unattractive, but within, when the 



