118 MB. CONRAD'S DESCRIPTIONS 



An elegantly formed and very rare speciet, dedicated to James D. Anderson, Esq., 

 of Vicksburg, who first collected the fossils of that locality and studied the species. 



CANCELLARIA. 



C. MississippiENSis. P]. 11, fig. 38. — Subovate; whorls five or six, turreted j ribs prominent, ten or eleven 

 on the large volution, one or two considerably larger than the others ; revolving lines raised, distinct, 

 alternated in size on the lower half of the body whorl ; labrum striated within; columella concave, 

 three-plated. Length i. 



C. FUNERATA. PI. 11, fig. 39. — Obloug-ovate, with large longitudinal ribs and prominent revolving lines; 

 spire rather elevated, turreted, whorls six, convex; two from the apex entire ; ribs on the body whorl 

 profound, unequal ; labrum with nine prominent lines within not extending to the margin ; columella 

 three plaited. Length 1. Very rare. 



TRITON. 



T. CRASSiDENS. PI. 11, fig. 40. — Subfusiform, a little distorted; spire acuminated; whorls latticed, the 

 longitudinal ridge rather distant, prominent ; body whorl M'ith the longitudinal ribs distant, and 

 on the angle some of them very prominent or subtuberculous ; labrum with one large thick prominent 

 tubercle, and with transverse plates and grains ; columella profoundly excavated ; canal short. 

 Length 1 6-10. 



I have given the name of crassidens to this species to distinguish it from T. 

 cancdlinus, the large tooth on the labrum being very thick and prominent. The large 

 j)late on the upper part of the labium is much smaller than the corresponding one in 

 cancellinus. It differs in other particulars though the two species are nearly allied. 



T. ABBREViATUs. PI. 11, fig. 42. — 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, and 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. 



T. MISSISSIPPIENSIS. PI. 11, fig. 41. — Acutely subovate; volutions six or seven, latticed, the longitudinal 

 and revolving lines subequal ; one varix on the large volution opposite to that on the submargin of the 

 labrum, both elevated, 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 i nearly. 



Of this species I obtained one specimen only. 



CASSIDARIA. 



C. LiNTEA. PI. 11, fig. 43. — Elliptical, with fine closely-arranged revolving lines, crossed by finer 

 longitudinal 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 margin ; labium striated above, and with rugose plaits below ; submargin 

 of labium striated within, margin entire. Length li. 



