CRETACEOUS PERIOD. 195 



which it will be seen to be considerably smaller than the maximum size of 

 Mr. Meek's specimens. It differs somewhat also from his description in 

 having its radiating furrows more irregularly disposed upon the anterior 

 part of the shell, but this is regarded as only an individual variation. 



Family TURRITELLID^. 



Genus TURRITELLA Lamarck, 1801. 



Turritella uvasana Conrad. 



Plate XVIII, fig. 11 a and 6. 



Turritella uvasana Conrad, 1856, Pacific Railroad Surveys, v, 321. 

 Turritella uvasana Gabb, 1864, Paleontology of California, i, 134. 



Shell of ordinary size, elongate, slender ; sides straight ; volutions nu- 

 merous, apparently reaching eighteen or twenty in number when full-groT\ai ; 

 the sides of the volutions nearly straight or only slightly convex ; suture 

 broad, deeply impressed. 



Surface marked by numerous revolving raised lines, six or eight of 

 which are moderately large, the smaller ones alternating with them. The 

 larger lines are minutely nodose upon the larger volutions, and upon the 

 last one they are sometimes even subspinulose. 



All the specimens of this species in the collection are more or less 

 broken, but, judging from the apical angle indicated by their sides, the 

 largest one must have been about five and a half centimeters long, and its 

 last whorl about thirteen millimeters in diameter. 



I have referred this species to T. uvasana Conrad with some doubt, for 

 several reasons. Both Conrad's and Gabb's descriptions are unsatisfactorily 

 short : Conrad's figure is of only a fragment ; Gabb's figure is proportionally 

 more slender than any of our examples ; and, finally, Conrad refers his species 

 to the Eocene period. Gabb, however, obtaining his specimens from the 

 typical locality, in Los Angeles County, California, refers the strata there 

 to the Cretaceous period. 



Position and locality. — Strata of the Cretaceous period; southeast of 

 Paria, Utah. 



