MAZATLAN BIVALVKS 23 



Hah. — Panama and St. Bias, 33 fm. B. B. Kinds, Mus. Cum- 

 ing. — Mazatlan : one small pair nestling in Spondylus, and 

 1 valve in ChamEe, L'pool Col. 



There is no doubt that the Mazatlan shell is the same as 

 Mr. Cuming's beautifid specimen, hitherto undescribed. Tablet 

 77 contains the perfect specimen ; I reserve the valve. 



33. CoEBULA PoVFLATA, SoiC. 



Proc. Zool. Soc. 1833, p. 35, 26.-311111. Si/n. Test. Viv. p. 230.— 

 Rve. Conch. Ic. pi. 1. f. 7. — Hani, in Supjil- Wood's Lid. Test. 

 pi. 10, f. 52.— jfffm?. Bescr. Cat. v- 4>7.—B. M. Cat. UOrh. 

 Moll. p. 70, no. 622. 



Tablet 78 contains 1 flat dead valve of regular oval shape 

 shghtly produced anteriorly, and verv finely striated concen- 

 trically, which may belong to this species. 



Hab. — In sandy mud, 7 — 17 fm. Xipisapi, and Bays of Montijo 

 and Caraccas, Cuming.*— TLcuadiov: Xipisapi, D'Orhir/ny. — 

 Taboga, very rare but large, C. B. Adams. — Mazatlan ; 

 one valve, L'pool Col. 



34. CoEBtJLA , s}}. ind. 



Tablet 79 contains a fragment of what must be when perfect 

 a most beautiful and remarkable species. It is extremely thin, 

 white, translucent, with a ver\- sharp diagonal i^osterior keel, 

 and another close to the margin. Umbos very near the anterior 

 end. Shell smooth near the umbos ; afterwards with waved 

 concentric ridges ; posterior part with deep pits at a sharp 

 angle with the ridges. The whole shell with radiating rows of 

 dots (probably epidermal) as in C. pustulosa. Inside a stout, 

 somewhat conical tooth in each valve, with corresponding pit. 

 Interior surface verj' finely rugose. Mr. Hanley found a mucli 

 more i^erfect specimen, which was most imfortunately crushed 

 in transmission by the post. 



Hah. — Mazatlan ; from Spondylus Lamarckii ; L'pool Sf Havre 

 Coll. 



* Mr. Reeve further states "A few odd valves of this species \rere found bii 

 Mr. Cuming on the sands at Real Llejos and Mazatlan." In reference however 

 to this last locality, Mr. Cuming states that his extreme point north, along the 

 West American coast, was Conchagua, Bay of St. Carlos (or Fonscca) : about 13 " 

 N. L. In all cases therefore where he is cited as the original collector at places 

 north of this, the authority must be regarded as " Museum Cuming." 



