MAZATLAN UNIVALVES 299 



349. HlPPONYX BAEBATUS, Sow. 



Proc. Zool. Soc. 1835, p. 5 :Tkes. Conch. (Brachiopoda,) p. 369, 



pi. 73, f. 26, 27. C. B. Ad. Pan. Shells, p. 217, no.' 327. 



Proc. Zool. Soc. 1856, p. 3, no. 3. 

 ? = Hipponyx australis, Mice, in Zeit. f. Mai. 1847, p. 186, 



no. 38 : non H. australis, Desk. = 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 striae, 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 a row of bristly hairs. Inner margin rounded, 

 crenulated by the ribs outside. Colour white, more or less 

 tinged with rufous brown Long. *65, lot. '54, alt. '22. 

 Hob. 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 



calcifer, &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. HIPPONYX (AMALTHEA) GEAYANUS, Mice. 



Zeit.f. Mai. 1853, p. 115. Proc. 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. Mai. 1853, 

 p. 79. (Non H. radiata, Quo?/ fy G-aim, 1824 : nee H. radiata, 

 Desk. 1830, in Lam. An. s. Vert. vol. vii. p. 616, no. 6 ; = 

 H. crispa, Mice. 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, 



