288 [Oct. 1847. 



2. Triton abbreviatus. 



Short-subovate : whorls six, longitudinally ribbed, and with strong alternated 

 revolving lines ; whorls of the spire slightly convex, the two nearest the apex 

 entire, rounded body whorl inflated, anJ having one large varix ; the ribs 

 about fifteen in number ; submargin of labrum denticulate ; canal short, oblique, 

 straight, aperture and canal about half the length of the shell. Length 4-10. 



3. Triton Mississippiensis. 



Acutely subovate ; volutions six or seven, latticed, the longitudinal and re- 

 volving lines subequal ; one varix on the large volution opposite to that on the 

 submargin of the labrum, both elevated and narrow or subcompressed : two 

 varices narrow and prominent on three whorls of the spire ; submargin of labrum 

 with six teeth ; columella with five transverse plaits, and two or three near the 

 upper angle of aperture. Length J nearly. 



Of this species I obtained one specimen only. 



Cassidaria lintea. 

 Elliptical, with fine closely-arranged revolving lines, crossed by finer longi- 

 tudinal lines, most distinct towards the margin of the labrum ; spire prominent, 

 acute, cancellated ; penultimate whorl slightly tuberculated at base ; angle of 

 large whorl with unequal small tubercles, wanting towards the labium mar- 

 gin ; labium striated above, and with rugose plaits below ; submargin of labi- 

 um striated within, margin entire. Length \\. 



1. Cassis ccelatura. 



Short-elliptical, with revolving lines and serious of nodes and granules ; 

 tubercles profound on the angle of the body whorl ; spire prominent, whorls 

 cancellated ; the upper half with a profound revolving line ; labium granulated 

 and striated throughout, the upper grains indistinct ; labrum with transverse 

 prominent lines. Length 1^. 



2. Cassis Mississippiensis. 



Subovate ; whorls sightly concave above, the angle nodular; body whorl 

 indistinctly ribbed or waved ; revolving lines distinct but fine ; body whorl 

 with one sharp compressed varix or carina ; apex papillated ; pillar with trans- 

 verse rugose plaits throughout ; submargin of labrum regularly and profoundly 

 dentate. Length 9-10. Very rare. 



Oniscia harpula. 

 Obovate, latticed ; longitudinal ribs angular, distant, about ten on the large 

 whorl, with a slightly foliated and waved margin ; revolving lines large, dis- 

 tant, about twelve on the body whorl ; spire scalariform, the ribs divided by an 

 impressed line ; submargin of labrum obtusely dentate. Length 1 2-10. Very 

 rare. 



Fulgoraria Mississippiensis. 



Elliptical, volutions nine, fluted, the ridges distant, acute, and generally one 

 or two of them large, thick and very remote from each other, on the body whorl; 

 spire conical, acute ; aperture auriform ; columella with nearly equal plaits, 

 not oblique ; labium thick, with a sharp margin. Length 1J. Common, 



