154 NASSID^. 



the Mala3^sian Archipelago, etc. They live with the Nassas 

 along shore-lines and do not appear to inhabit great depths. 

 The animal, which is unknown, is supposed, from the sutural slit 

 which characterizes the shell, to possess a mantle provided with 

 a prolongation or fold occupying the slit, somewhat analogous, 

 perhaps, with that of Oliva. The operculum of G. lyrata is 

 elongated, rhomboidal, with terminal nucleus, externally con- 

 cave, internally convex. 



CYLLENiNA, Bcllardi, 1882. Spire more produced, the last 

 whorl about half the length of the shell ; parietal wall of the 

 aperture concave, without lip ; columella terminating anteriorly 

 in an oblique truncation, which is usually ridged. 12 sp. Ter- 

 tiary ; Northern Italy. C. Ancillariseformis, Grat. Appears 

 to connect Cyllene with Nassa. 



BucciTRiTON, Conrad. 



Syn. — Sagenella, Conrad. 



Diatr. — B. cancellatum^ Lea = sagenuvi, Conr. (li, 73 ). Eocene ; 

 Alabama. 



Genus not characterized. One of the typical specimens of B. 

 sagenum has a single varix on the back of the body-whorl, but 

 the other specimens are without it, so that its non-absorption 

 may be regarded as accidental. B. altum is a different type of 

 shell entirely, and looks something like a Truncaria. 



Family NASSIDJE. 



Shell ovate, spire usually elongated, base of aperture a notch 

 or short recurved canal, inner lip usually callous. Operculum 

 corneous, ovate, nucleus apical, margins plain or serrated. 

 Animal having two small processes or tails at its posterior 

 extremity. Lingual teeth arched, pectinated ; the uncini with 

 a basal horn, and occasionally intermediate serrations. Dentition 

 (X, 13). 



Many fossil species are known, commencing with the Eocene. 



NoRTHiA, Gray, 



DiHt7\ — 3 sp, Panama, Philippines, N. serrata, Dufresne 

 (Hi, 74^. 



Shell elongated, turreted, polished ; spire elevated, acuminated, 

 whorls depressed and sloping at their upper part ; aperture 

 shorter than the spire ; outer lip with the margin serrated. 

 Dentition imknown. 



This genus is in its general aspect much closer to Pusionella 

 in the family Terebridae than to the genera with which it is here 

 (and has been heretofore) associated; the variceal thickening 

 at or near the outer lip is, however, a feature whi(jh does not 



