HALTOTID^. 325 



single spiral series ; interior pearly, with a large central muscular 

 scar. No operculum. 



Animal with a short muzzle and subulate tentacles ; eyes on 

 pedicels at the outer bases of the tentacles ; branchial plumes 2 ; 

 mantle-margin with a posterior (anal) fold or siphon, occupying 

 the slit or perforation in the shell. . Operculum lobe rudimen- 

 tary ; lingual dentition similar to Trochus. 



The species are remarkable for the beauty and variety of their 

 shells and are mostly tropical in distribution. One small species 

 is eaten by the inhabitants of the Channel Islands (Gt. Britain), 

 and others are important articles of diet in China, Japan, and 

 among the Chinese settled in California. The shells are largely 

 used for the manufacture of mother-of-pearl ornaments and for 

 inlaying in papier-mache work. 



Haliotis, Linn. 



Ear-shell. Etym. — Halios, marine, and ous (otos), an ear. 



Distr. — 75 sp. Britain, Canaries, Cape, India, China, Aus- 

 tralia, New Zealand, Pacific, California. Fossil, 4 sp. Creta- 

 ceous. H. Midse, Linn. (Ixxxiii, 10). H. gigantea, Chemn. 

 (Ixxxiii, 11), 



Shell ear-shaped, with a small flat spire; aperture very wide, 

 iridescent; exterior striated, dull ; outer angle perforated by a 

 series of holes, those of the spire progressively closed. 



Animal with fimbriated head-lobes ; side-lobes fimbriated and 

 cirrated ; foot very large, rounded. Lingual teeth, median 

 small ; laterals single, beam-like ; uncini about seventy, with 

 denticulated hooks, the first four very large. 



DERiDOBRANCHus, Ehrenberg. Shell large and thick, like 

 Haliotis, but entirely covered by the thick, hard, plaited mantle 

 of the animal. D. argus. Red Sea. 



TEi NOTTS, H. and A. Adams. Shell depressed, elongated, ear- 

 shaped ; spire small, and placed posteriori}^ ; hinder part of the 

 foot in the animal stretches far over the shell. 2 sp. East 

 Indies. H. asinina, Linn. (Ixxxiii, 12). 



PADOLLUS, Montfort. A strong, rounded, spiral rib within the 

 line of perforations, and forming a spiral sulcus inside the shell. 

 Form rounded-oval, with rather large, sublateral spire. H. tri- 

 costalis, Linn. (Ixxxiii, 13). 



SULCULUS, H. and A. Adams. Very like Padollus, having the 

 same dorsal rib, but the form of the shell is more elongated, and 

 the spire smaller and subterminal. H. Janus^ Reeve (Ixxxiii, 14). 



Suborder EDRIOPTHALMA. 



Shell conical, not spiral, porcellanous. No operculum, Ej-es 

 sessile. 



