746 



NORTH AMERICAN INDEX FOSSILS. 



CXXXII. Nerinella Sharpe. 

 Like Nerinea but with columellar fold generally wanting ; a fold 

 commonly occurs on the inside of the outer lip. Jurassic- 

 Comanchic. 

 475. N. stantoni Craigin. (Fig. 1079, c-e.) Jurassic. 





Fig. 1080. a, Nei-inea austinensis ; b, N. cullri- 

 spira. (After Roemer. ) 



Fig. 1081. Nerinella 

 subula. (After Roemer/ 



Exceedingly slender ; whorls with gently concave sides bearing 

 four equidistant spirals ; upper and lower angulations sharp and 

 appearing as spirals. No columellar fold but a blunt one on inner 

 side of outer lip. 



Malone formation of Texas. 

 476. N. subula (Roemer). (Fig. 1081.) Comanchic. 



Slender and subulate ; suture scarcely depressed ; sides of 

 whorls flat with two (more rarely three) rows of small tubercles on 

 the basal portion of the body whorl ; aperture elongate. No 

 columellar or labial folds. 



