HAZATLAN BIVALVES 23 



Hal) Panama and St. Bias, 33 fm. E. B. Hinds, Mus. Cum- 

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

 1 valve in Chamae, L'pool Col. 



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

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

 77 contains the perfect specimen ; I reserve the valve. 



33. CORBULA POVULATA, Sou). 



Proc. Zool Soc. 1833, p. 35, 36.MHIL St/n. Test. Viv. p. 230. 

 Rve. Conch. Ic. pi. 1. f. 7. Hani, in Suppl. Wood's Ind. Test. 

 pi. 10, f. 52. Hani. Descr. Cat. p. 47. B. M. Cat. D'Orb. 

 Moll. p. 70, no. 622. 



Tablet 78 contains 1 flat -dead valve of regular oval shape 

 slightly produced anteriorly, and very finely striated concen- 

 trically, which may belong to this species. 



Hob. In sandy mud, 7 17 fm. Xipixapi, and Bays of Montijo 

 and Caraccas, Cuming* Ecuador: Xipixapi, D'Orbigny. 

 Taboga, very rare but large, C. B. Adams. Mazatlau ; 

 . one valve, Lpool Col. 



34. CORBULA , sp. 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 very sharp diagonal posterior 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 very finely rugose. Mr. Hanley found a much 

 more perfect specimen, which was most unfortunately crushed 

 in transmission by the post. 

 Hob. Mazatlan ; from Spondylus Lamarckii ; L'pool fy Havre 



Coll. 



* Mr. Eeeve further states "A few odd valves of this species were found lit 

 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 Fonseca) : 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." 



