TROCHUS. 285 



Identical with the species described by Mr. Sowcrby, " Conch, 

 lllustr.," fig. 7, under the above name. AUhough Mr. Sowerby's 

 figure agrees well with our shell, his descri}3tion does not in all 

 resi)ects. For instance, " anfractibiis quinquey Our shell has but 

 four turns. Again, " Long. 0.55, lat. 0.5 poll." Thus we see that 

 Mr. Sowerby's shell is not only twice as large as our specimen, but 

 proportionalbj higher. The breadth of our shell in its longest basal 

 diameter is greater than the height. But as we have only a single 

 specimen, we prefer to pui^lish it with the assumption that it is iden- 

 tical with M. acuminata, rather than produce confusion by hazard- 

 ing a new name for an old shell. {Mig-hels and Adams.} 



Margarita varicosa. 



Shell small, thin, conic ; whorls four, convex, longitudinally ribbed, transversely 

 striate; suture sub-canaliculated ; umbilicus large, deep. 



Margarita varicosa, Mighels and Adams, Bost. Journ. Nat. Hist. iv. 46, pi. 4, fig. 14 

 (1842).— Stimpson, Check List:,, 4. 



Shell small, thin, low, conical, of a dingy white or drab color ; 

 whorls four, convex, covered with numerous longitudinal, 

 oblique ribs, intersected by a great number of transverse, ^'s-^^''- 

 revolving striae, which are most conspicuous on the lower 

 part and base of the lower whorl. The striae on the upper 

 part of the whorls can only be seen with a magnifier. Sut- 

 ure distinct, sub-canaliculate ; umbilicus rather large and 

 deep, bounded by two rather rugged varices, intersected by the ribs 

 which are continued to the verge of the umbilicus ; aperture circu- 

 lar ; labrum simple, sharp ; within perlaceous. Height, twenty-five 

 hundredths of an inch ; diameter of base equal to the height ; di- 

 vergence, ninety degrees. (^Mighels and Adams.} 



Bay Chaleur, taken from the stomach of a codfish {Mighels and 

 Adams') ; Fishing Banks (^Willis). 



Oeiiiis TROCHUS, Lin. 1758. 



Shell conical, axis imperforate, last whorl angulated at the 

 periphery ; columella superiorly spirally twisted, forming a canal, 

 anteriorly simple, straight, ending in a point. 



