GASTROPODA 



531 



Family 1. FISSURELLIDAE. 



Keyhole limpets. Shell non-spiral, conical; either anterior margin 

 notched or apex perforated; 2 symmetrical ctenidia ; foot very large, 

 with an epipodial ridge on each side, which bears a series of cirri; no 

 operculum: several hundred species. 



FissuRELLA Bruguiere. Apex of shell perforated; 

 shell wholly external, capable of containing the whole 

 animal: 125 species, mostly in warm waters. 



F. barbadensis Gmelin (Fig. 823). Shell oval, per- 

 foration almost circular; surface with radiating ribs, of 

 which about 11 are larger than the others ; color grayish 

 inside, with alternatelj^ green and white concentric rings ; 

 margin crenulated; length 37 mm.; width 24 mm.; height 9.5 mm.: 

 Florida, Bermuda, and West Indies; common. 



F. volcano Reese. Shell oval; orifice a little in front of the middle 

 and oblong; color grayish, with 13 to 16 radiating purplish rays; length 

 25 mm. ; width 17 mm. ; height 10 mm. : Santa Cruz, California, and 

 southwards. 



Family 2. HALIOTIDAE. 



Ear shells. Shell ear-shaped, the spire being flat and the aperture 

 enormously expanded, and perforated with a spiral series of holes near 

 the left margin; no operculum; eyes on stalks near the outer base of 



the tentacles ; foot very large, 

 surrounded by fringed and 

 tentacled epipodia, which 

 project beyond the edge of 

 the shell and through the 

 holes; right gill smaller than 

 the left: 1 genus and about 

 100 species; the animals are 

 eaten in many places, and 

 the shells are much sought 

 after on account of their 

 beauty and for use in the 

 manufacture of buttons and 

 buckles and for inlaying. 

 Haliotis L. Abalones. With the characters of the family: Pa- 

 cific and Indian oceans and Europe; about 5 species on the Pacific 

 coast, living in shallow water. There is large export trade in the shells 

 and flesh of these animals, the latter being dried and sent to Japan and 

 China, the shells to Europe. 



Fig. 824 — Haliotcs fulgens (Rogers). 



