260 [January, 



MITRA, Eumph. Lam. 

 Subgemis Lapparia, Conrad. 



Short-fusiform, spinous; apex papillary; beak very short, thick, twisted; 

 plaits as in Mitra. 



M. (Lapparia,) dumosu, PI. xv., fig, 4. Short-fusiform, volutions seven, 

 direct, obliquely flattened above, with a series of transversely compressed, distant 

 spines on the two largest whorls ; on the contiguous whorl they become nodules ; 

 two whorls below the apex papillary, smooth ; the next two longitudinally ribbed, 

 and the others longitudinally striated or with prominent lines of growth; whole 

 surface with revolving wrinkled lines ; plaits four ; beak profoundly ridged. 



CONUS, Lin. 



C. tortilis, PI. xv., fig. 5. Ovato-turbinate ; spire obtusely conical with the 

 apex exserted, acute; whorls obliquely flattened, with revolving impressed lines 

 and transverse wrinkles, carinated near the base, direct between the carina and 

 suture; lines of growth on body whorl profoundly curved; base with a pro- 

 found thick fold. 



Differs from C. sanrodens, Con., in having a more prominent and convex spire, 

 in the large twisted callus at base, &c. 



ROSTELLARIA, Lam. 



1. R, velata, Con., PI. xv. fig. 7. R. Lamarckii, Lea, Cont. fig. 164. 



2. JR. slaminea, PI. xvi. fig. 9. Fusiform, spire elongated, subulate abo^e ; 

 whorls fifteen; body whorl slightly concave with fine closely-arranged revolving 

 lines, and obsolete longitudinal undulations ; three upper whorls with curved 

 longitudinal acute ribs; the remainder covered with a polished calcareous de- 

 posit, and excavated at the suture ; body whorl angular on a line with the upper 

 margin of the aperture; labrum thin ; beak slightly curved. 



This species occurs at Claiborne in great abundance. 



VOLUTALITHES, Swains. 



1. V. symmetrica ^YX. xv., fig. 8. Subfusiform ; with longitudinal acute ribs 

 terminating above in short spines on the body whorl ; volutions excavated above, 

 where they are striated but not ribbed ; body whorl with raised alternated revolv- 

 ing distinct lines; above the angle they become almost microscopic; suture 

 margined below by a series of small points, and somewhat carinated ; plaits 

 three, slender. 



Allied to V. Sayana, Con. 



NATICA, Lam. 



N. permunda, PI. xvi., fig. 2. Suborbicular ; body whorl somewhat excavated 

 near the suture ; spire very short ; umbilicus very long, profound, with a central 

 broad rounded ridge, and the lower margin subcarinated ; columella subrectilinear. 



APORRHAIS. 



Subgenus Platyoptera, Conrad. 



Shell with a profoundly expanded labrum which is entire, or without a rostrum, 

 and with the margin very thin and acute. 



A. (P.) eztenta, PI. xvi., fig. 3. Shell independent of labrum fusiform, with 

 prominent revolving rounded lines and intermediate fine lines, from one to three, 

 and longitudinal microscopic lines ; volutions rounded, covered towards the apex 

 with a polished calcareous deposit ; labrum within with impressed radiating 

 lines, becoming well marked furrows towards the base. 



