MAZATIAN rNIVALVES 499 



Tablet 2400 contains 2 young shells and a fragment which 

 probably belong to this species. The first 3 whirls are smooth 

 and rather globose ; then fine sharp ribs appear, which soon 

 become fenestrated by spiral lines which increase in number, 

 and finally develop granules at the intersections. 

 ^a5.— Panama, 1 sp. C. B. ^rfams.— Mazatlan ; portions of 



5 specimens, ofi" Spondylus ; L'pool Col. 



632. Nassa Pveesicoloe, C. B. Ad. 



Pan. Shells, pp. 66, 305, no. b^.—Bve. Conch. Ic. pi. 17, f. 110. 

 (Nassa) Uzita versicolor, H. 8f A. Ad. Gen. i. 120. 



Tablet 2401 contains fragments which may belong to this 

 species. 

 JTai.—Taboga, common, C. i?. ^cZa?^*.— ? Mazatlan ; extremely 



rare, fragments ofi" Spondylus ; L'pool Col. 



633. Nassa ceebeisteiata, n. s, 



N. t. acuminata, flavido-fusca, solidiore ; anfr.^ normalibus 

 vi. parum rotundatis, suturd distincta ; costis circiter x. acutis, 

 distantihus, sx)arsim varicosis, aperturam versus haud ohsoletis ; 

 striulis spiralihus creherrimis, exillimis ornata ; aperturd suh- 

 rotundatd ; labro varicoso, inius crebre lirulato, juxta canalem 

 lira extante ; labio haud rejlexo, parum extante ; tuberculo 

 parietali parvo ; 2^licd acuta canalem recurvatum valde extan- 

 tern dejiniente. 



The only specimen found, covered with Bryozoa in the 

 upper whirls, has the aspect of N. incrassata, from which and 

 cognate species it differs in the extreme fineness of the spiral 

 sculpture. Loncf. '54, long. spir. "32, lat. '3, div. 37". 

 Hab. — Mazatlan ; 1 fresh sp. L'pool Col. 



Tablet 2402 contains the specimen. 



634. Nassa ■ , sp. ind. (f.) 



Tablet 2403 contains a small, imperfect specimen resembling 

 N. crebristriata ; but red, with the spire less elevated, and the 

 ribs broad and blunt. 

 jBTrtJ.— Mazatlan ; 1 sp. off Spondylus ; L'l^ool Col. 



