MAZATLAN UNIVALVES 299 



349. HiPPONYX BAEBATUS, Sow. 



Proc. Zool. Soc. 1835, p. 5 -.—Thes. 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, Mke. in Zeit. f. Mai. 1847, p. 186, 



no. 38 : non H. australis, Desk. = Patella australis, Lam. 



Shell commencing as a lielicoid body witli 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 ia Helix. The spiral part remains longer than in most 

 Hipponices ; the sheU 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 ia 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, lat. "oi, alt. '22. 



Sah. — Coral reefs round Toobouai, Soc. Is. Cef mwr;'.- 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 Mure« 

 princeps, very elongated form. 



350. HippoNTx (Amalthea) Geayanus, MJce. 



Zeit.f. Mai. 1853, p. 115.— Proc. Zool. Soc. 1856, p. 4, no. 4. 



Hipponyx radiata, Gra//, Proc. Zool. Soc. 1835. — C. B. Ad. 

 Pan. Shells, p. 218, no. ^29. — Mke. in Zeii. f. Mai. 1853, 

 p. 79. (Non H. radiata, Quo?/ Sf Gaim. 1824 : nee H. radiata, 

 Desh. 183-0, in Lam. An. s. Vert. vol. vii. p. 616, no. 6; = 

 H. crispa, .MXt. 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 weU developed specimens, the ribs are fewer, 

 coarser and more nodulous than in H. barbata. The epidermal 

 hairs are softer, smaller, fewer, and inregularly scattered. The 

 apex is subcentral. Base rounded within, flattened externally, 



