HALIOTIDA. 325 
single spiral series ; interior pearly, with a large central muscular 
sear. 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. Opereulum 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-maché work. 
Hatrorts, Linn. 
Ear-shell. Htym.—Halios, marine, and ous (ofos), an ear. 
Distr.—i5 sp. Britain, Canaries, Cape, India, China, Aus- 
tralia, New Zealand, Pacific, California. Fossil, 4 sp. Creta- 
ceous. H. Mide, Linn. (Ixxxili, 10). A. 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. 
TEINOTIS, H.and A. Adams. Shell depressed, elongated, ear- 
shaped ; spire small, and placed posteriorly ; hinder part of the 
foot in the animal stretches far over the shell. 2 sp. Hast 
Indies. HA. asinina, Linn. (lxxxiii, 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. trv- 
costalis, Linn. (Ixxxiii, 13). 
sutcuLus, 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 (I1xxxiii, 14). 
SuporpeR HDRIOPTHALMA. 
Shell conical, not spiral, poreellanous. No operculum. Eyes 
sessile. 
