MAZATLAN UNIVALVES 299 
349. Hiprponyx BARBATUS, Sow. 
Proc. Zool. Soc. 1835, p. 4 :— Thes. Conch. (Brachiopoda,) p. 369, 
pl. 73, f. 26,27.—C. B. Ad. Pan. Shells, p.217, no. 327.— 
Proc. Zool. Soc. 1856, p.3, no. 3. 
?=Hipponyx australis, MWke. in Zeit. f. Mal. 1847, p. 186, 
no. 38: non H. australis, Desh.= Patella australis, Lam. 
Shell commencing as a helicoid body with nearly two whirls ; 
apex more or less sunken; smooth, with the lip entire as in 
Cyclostoma. It then spreads out, develops slight stric, and 
long star-like rows of hairs, the mouth expanding downwards 
as in Helix. The spiral part remains longer than in most 
-Hipponices ; the shell also is elongated. A young specimen 
had eaten its way into the shell of Murex princeps, without 
shelly attachment, as in Amalthea. No attachment was found 
with the adult shells, while in Mr. Cuming’s specimens it is. 
enormous. Shell when mature with close nodulous ribs, each 
armed with arow of bristly hairs. Inner margingrounded, 
crenulated by the ribs outside. Colour white, more or less 
tinged with rufous brown ong. °65, lat. ‘54, alt. °22. 
Hab.—Coral reefs round Toobouai, Soc. Is. Cuming.— Panama ; 
on stones and shells near low water mark, rare; C. B. Ad- 
ams.—Mazatlan ; young rare, adult very rare, on Spondylus 
ealcifer, &c.; L’pool Col. 
Tablet 1471 contains 6 sp. extremely young, the smallest °02. 
across.—1472, 5 sp. different ages.—1473, 2 sp. jun. off Murex 
princeps, very elongated form. 
350. Hiprponyx (AMALTHEA) Grayanus, Whe. 
Zeit. f. Mal. 1853, p. 115.—Proe. Zool. Soc. 1856, p%4, no. 4. 
Hipponyx radiata, Gray, Proc. Zool. Soc. 1835.—C. B. Ad. 
Pan. Shells, p. 218, no. 329.— Mke. in Zeit. f. Mal. 1853, 
p. 79. (Non H. radiata, Quoy & Gaim. 1824: nec H. radiata, 
Desh. 1830, in Lam. An. s. Vert. vol. vii. p. 616, no. 6;= 
H. crispa, Mke. loc. cit.) 
Only one small dead shell was found, which probably be- 
longs to this species. Although only ‘06 across, the apex is 
decollated. In well developed specimens, the ribs are fewer, 
coarser and more nodulous than in H. barbata. The epidermal 
hairs are softer, smaller, fewer, and irregularly scattered. The 
apex is subcentral. Base rounded within, flattened externally, 
