ACADEMY OF NATURAL SCIENCES 137 



Shell conical, spire somewhat elevated, nuclear whorls smooth ; other whorl 

 sloping above, truncated on the margin, nearly flit below ; surface marked by 

 numerous, finely granulated, revolving ribs ; color yellowish brown, banded by a 

 variable number of spiral purple lines, interrupted by white spots ; aperture sub- 

 quadrate, nacreous within ; inner lip heavy, outer lip and base acute, umbilicus 

 white. 



Hab. San Pedro, five alive on the sand shoal ; and Half Moon Bay, beach ; also 

 San Diego. Dr. Cooper. Also fossil in the Post Pliocene, San Pedro. 



No. 602, Mollusca, Survey Cabinet. 



The brown lines are variable in number, the under side of one specimen show- 

 ing two and of another six of these lines. The granulation of the ribs is arranged 

 in the lines of growth. 



N. Gen. PTYCHOSTYLIS, G. 



Testa Calliostomati similis, conoidea ; spira elevata ; apertura subquadrata ; co- 

 lumella antice truncata, plicis obliquis duabus induta, labro acuto, umbilico nullo. 



Shell resembling Calliostoma, Swains, (Zizyplrinus, Gray,) conical not umbili- 

 cate, internally pearly, spire moderately elevated ; aperture subquadrate ; colu- 

 mella bearing two oblique folds, the lower of which ends abruptly at the end of 

 the columella^ outer lip and base acute, smooth or internally striate ; operculum 

 unknown. 



P. CAFFEA, G. 



T. conoidea, tenui; spira elevata; anfr. I nucleari, lsevi, anfr. V ad marginem 

 subangulatis, supra recte declivis, ultimo infra sub-planato ; sutura valde impressa; 

 tota superficie concentrice tuberculato costata; costis circitur XVIII ad ult. anfr.; 

 epidermide flavida; apertura oblique sub-quadrata, intus albida. 



Long. -55, lat. 58, long. aper. -26, lat. aper. -28, ang. diverg. 58°. 



Shell conical, thin ; spire elevated ; one nuclear whorl, smooth, five perfect 

 whorls, subangulated at the margin, obliquely flat above ; body whorl very slightly 

 convex at the base ; suture strongly impressed ; surface marked by revolving tu- 

 bercular ribs, about eighteen on the body whorl, one broad one on the margin and 

 about eight or nine on the under side ; these ribs are less numerous on the pi-eced- 

 ing volutions, only four can be counted on the upper side of the penultimate 

 whorl ; the tubercles are arranged so as to present an irregular quincunx ; epider- 

 mis a rich coffee brown, darker between the tubercules than on their summits; 

 aperture obliquely quadrangular, outer lip and base acute, internally pearly white, 

 columella bearing two strong folds, the lower one of which borders the truncated 

 end and terminates in a faint tubercular enlargement ; behind the columella is a 

 slight groove running from the base to the end of the upper columellar fold. 



Hab. Monterey, 20 fms. Dr. Cooper. Also fossil, not rare, in the Post Plio- 

 cene of San Pedro and Santa Barbara, where some specimens have been found an 

 inch in height. 



No. 355, Mollusca, Survey Clloection. 



This shell appears to be allied to the genera Calliostoma and Thalotia, from 

 which it is separated by the peculiar mouth. In the absence of the operculum, it 

 is impossible to define. its position certainly. 



