42b YORKSHIRE TYPE AMMONITES Nov. 



42. PSEUDOLIOCERAS WHITBIENSE, nov. 

 (Plate XLII) 



Original Description 



Stages, conch, oxycone ; periphery, 3c ; ornament, 4c. Whorls 

 slightly gibbous towards periphery, which carries a low septicarina with 

 a small depression on each side (periphery concavifastigate). Ornament, 

 somewhat broad, distant, sigmoidal ribs, of low relief, somewhat irregular, 

 and somewhat bunched in pairs. Umbilicus almost concave ; the walls 

 being planate, just the inner rim of each whorl makes a small feature. 



Distinction 



From A. compactilis, Simpson, No. 41, the whorls are stouter, 

 more gibbous towards periphery, which is not so sharp ; the ribs are 

 more pronounced, fewer, broader, and irregular. From P. gradatum, 

 S. Buckman, the more pronounced ornament, especially the ribs on 

 the inner part of whorls ; also the sides less definitely separated from the 

 carina. From A. wurttenbergeri, Denckmann, more inflated whorls 

 especially towards periphery ; more distinct ornament. 



Remarks 



This is very near to the species figured by Haug as A. compactilis ; 

 and it is evidently a form regarded by Simpson as belonging to his species. 



Its exact horizon is uncertain : it is not from the same bed as 

 A. compactilis (No. 41) ; its condition is more that of A. lecius, 

 (No. 43). 



Result 



PSEUDOLIOCERAS WHITBIENSE, nov. [Whitbian, lilli-variahilis zone ? 

 Peak] near Whitby. 



