300 MAZATLAN TTiriVALVE3 



where it is crenated by the ribs, with numerous lamellse, 

 undulated, not serrated. 



Sab. — Gallapagos, Cuming. — Sandwich Is. on Pinna, Nuttall. — 

 Panama, 16 sp. on stones, near low water mark ; C. B. Ad- 

 ams. — S. W. Mexico, on Pinna, P. P. C. — St. Vincent 

 (Guinea) Schmidt, teste Menke, — Mazatlan ; extremely rare ; 

 L'pool Col. 



Tablet 1474 contains the specimen. 



GEjrrs CAPULUS, Monif. 



Capulus, Conch. Syst. II. 54, 1810. — Phil. Handb. Conch. 



p. 188.—^. ^- A. Ad. Gen. i. 371. 

 Pileopsis, Lam. Extr. Cours. 1812. 

 Amalthea, pars, Schum. Ess-, p. 181, 1817. 



351. CAPiTLrs , sp. ind. 



Tablet 1475 contains 3 apical fragments which may be con- 

 specific, though they differ somewhat in sculpture and outline. 

 They appear nearly related to the W. Indian Patella militaris, 

 Linn. The vertex has two tumid helicoid whirls, of which the 

 •upper is prominent, in this respect differing from the supposed 

 young of Hipponyx serratus . 

 Hob. — Mazatlan ; 3 sp. on Spondylus ; L'pool Col. 



Family VEEMETIDiE. 



Neither animals, shells nor opercula in this family have yet 

 been studied b.y travelers, as much as from their diversity and 

 aberrant characters they deserve. The species are extremely 

 difficult to discriminate by the shells alone. Habit of growth 

 and colour appear to be of more consequence than the variable 

 details of sculpture. The figures of Chenu and Valenciennes, 

 unaccompanied by either description or geographical informa- 

 tion, are rather calculated to confuse than to aid the student. 

 Remarkable variations were found among the opercula, which, 

 from their occurring among the Spondylus washings, and from 

 their not being admissible in any other direction, appear to 

 belong to this family : but only in regard to two species can 



