OF CONCHOLOGY. 263 



referred to Tritia by H. and A. Adams, is also represented in 

 that locality and species are figured by Grateloup on his plate of 

 Buccins, fig. 16, 36, 40, and by Brocchi, pi. v., fig. 4, 9, 12. 

 Shell elongated, comparatively small. Species, T. trivittata., Say ; 

 T. varicosa, Con. ; T. peralta. Con. ; Buccinimi quadrulatum, 

 H. C. Lea ; Tritia impressa, Con. The siphonal canal as in 

 the last group almost undefined, and the interior of the labrum 

 either entire or striated, but not thickened. 



ILYANASSA, Stimpson. 



The shells of this group are often varicose, some having this 

 character prominent, as in fig. 36 of Grateloup's Buccins. This 

 character is also slightly developed in Nassa obsoleta, Say, and 

 P. irrorata, Con. 



I. IRKORATA. PI. 19, fig. 10. 



Proceed. Acad. Nat. Science, 1862, p. 562. 



Bucciniim ohsoletum. Tuomey and Holmes, (not Say.) 



Distinguished by the sculpture being more prominently gran- 

 ulose than in that of the recent species ; it is also a thicker shell 

 with a much thicker labrum. The minute granulations on the 

 polished inner lip of the /. obsoleta, are obscurely traced on the 

 weathered lip of the fossil. 



PTYCHOSALPINX, Gill. 

 R. SCALASPIRA. — PI. 19, fig. 4. 



Description. — Ovate ; body whorl profoundly ventricose, spire 

 scalariform, acute ; ribs small, numerous, oblique, not very prom- 

 inent, revolving lines obsolete on the penultimate and upper part 

 of the body whorl ; columellar fold very prominent. 



Locality. — Virginia. 



Collection of the Academy. One specimen. 



P. LiENOSA, Conrad. — (Tritia,) pi. 19, fig. 9. 

 Proceed. Acad. Nat. Science, 1843, p. 308. 



Subgenus PARANASSA, Conrad. 

 P. GRANIFERA. — PI. 19, fig. 6. 



Description. — Ovate, thick, with numerous oblique granulated 

 ribs and distinct impressed lines, about 9 on the body whorl ; 

 one or two filiform lines between the larger lines near the 

 suture ; spire short, whorls slightly turrited ; aperture with 6 

 prominent lines within ; beak carinated on the back. 



Locality. — Virginia. 



