669 Platyc. 



Platyceras insequale, new species^ Simpson, Trans. Am. 

 yjii^ ^'. Phil. Soc. Phila., 1886, 



^"'^' ,y . ^L^ ^-^?:-;^i>^ 3. p. 456, fig. 25, 1, front 



W- f W\ f ""^^N view; fig. 2, dorsal 



^^%, \ S^) / ' '% view ; fig. 3, side view. 



i^^-i-i.,;-^!^ V ^ ^w ---.._„^,...^^ Based upon Randall's 



^^^^^ specimen 9472 A, C, of 



Tr 1889. j^.g collections near 



Warren, Pa. — Description: Shell small, subangularly ovate ; 

 apex minute, incurved, making less than one turn, very thin 

 and angular ; inclined or twisted to the right. The body of the 

 shell expands rapidly ; anterior side curved, sometimes form- 

 ing nearly half a circle ; posterior side also curved, but in a 

 lesser degree; width of base from one-half to three-fourths 

 the length of the anterior side ; posterior side one-third the 

 length of the anterior. The left side is flattened or only very 

 slightly convex, and is often nearly or quite at right angles to 

 the base, making a sharp angle or ridge between the side and 

 the back of the shell. The right side is convex and much more 

 developed than the left. In front the shell becomes flattened 

 near the margin. On the left side, about half way between 

 the base and angular carina, there is a low, rounded ridge, 

 commencing near the apex and continuing the length of the 

 shell, though this feature in many of the specimens is obscure. 

 Aperture circular or broadly oval. Most of the specimens ob- 

 served are casts or macerated so that the surface characters are 

 obsolete. On some of the specimens there are evidences of 

 strong radiating striae or elongate pustules, and when well pre- 

 served there are numerous concentric striae. The characteris- 

 tics of this species are the pinched appearance of the apical 

 portion, and its inclination to the right, and the much greater 

 development of the right side ; in the latter feature it resem- 

 bles Platyceras cyinbeum^ but is a much smaller shell, and 

 the plications are very much less prominent; from Platyceras 

 rnitelliforme it may be distinguished by the inequality of its 

 sides, in that species the prominent ridge being in the middle 

 of the shell, both sides being equally developed. Four miles 

 northwest of Warren. Chemung upper beds. VIII g. 



Platyceras infundibulum, encrusted with Platycrinus 

 hemisphericus, which see for figure. 



