MOLLUSCA. 747 



1892. Pyropsis trochiformis (?) Whitf., Pal. N. J., vol. 2 

 (Monog. U. S. G. S., vol. 18), p. 41, pi. i, figs. 4-7. 



1892. Pyrvpsis Reileyi Whitf., Pal. N. J., vol. 2 (Monog. U. S. 

 G. S., vol. 1 8), p. 42, pi. 2, figs. 11-20. 



1905. Pyropsis trochiformis Johns., Proc. Acad. Nat. Sci. Phil 

 (1905), p. 23. 



Description. The dimensions of an incomplete internal cast 

 are : height, as far as preserved, 40 mm. ; probable total height, 

 about 60 mm. ; maximum diameter, 41 mm. Shell pyriform, with 

 three or four rapidly increasing volutions, spire depressed, the 

 first volution and one-half almost flat in the casts, suture in the 

 cast widely open. Body volution very broad and gibbous, con- 

 tracting somewhat rapidly below to the anterior canal, which has 

 been broken and destroyed in most of the specimens observed. 

 Surface of the outer volution rounded from the suture to* the base 

 of the anterior canal, that portion above the line of greatest width 

 shorter and more strongly convex than that below. Surface of 

 the casts smooth, but sometimes with slight indications of the 

 revolving costse of the exterior. Columellar cavity large in the 

 casts. External surface of the shell marked by strong, more or 

 less nodose, revolving costae, and by somewhat irregular lines 

 of growth, the revolving lines becoming gradually more slender 

 towards the base. 



Remarks. The original description of this species is as fol- 

 lows: "Shell top-shaped; body whorl large, inflated, covered with 

 revolving raised lines ; spire depressed, not flat ; angle of the body 

 whorl rounded ;. canal produced ; aperture nearly circular." 



The internal casts which Whitfield has illustrated as representa- 

 tives of this species are probably correctly identified, with the 

 possible exception of his figure 7, with the strong, revolving ribs 

 near the aperture, although these markings may be due to the 

 immature condition of this particular individual. It. is possible 

 that figure 6 of the same author is also incorrectly identified. In 

 addition to these, the specimens which Whitfield has described as 

 P. reileyi apparently belong here, and also the internal casts he 

 has identified as P. richardsom, which are totally different from 

 the true P. richardsoni of Tuomey. This species, in fact, includes 



