1913] Dickerson: Fauna of Eocene at Marysville Buttes 277 



TURRIS PERKINSIANA (Cooper) 

 Plate 11, figures 7a and 7b 



Pleurotoma perMnsiana Cooper. — Cooper, J. G., Catalogue of California 

 Fossils, California State Mining Bureau, p. 40. 1894. 



''Very long and slender; whorls about ten, rounded, the first two 

 turbinate, smooth; third with ten or twelve elose-set vertical riblets, 

 crossed by eight or ten revolving ones, the vertical gradually increasing 

 to twenty-six on the body-whorl, forming a close beaded sculpture as 

 far as the middle of body-whorl, while the revolving ribs continue alone 

 on the body to canal. Varies also in relative strength of the two series 

 of riblets, at different portions of spire. Sinus close to suture, canal 

 straight, columella simple. Length, 0.60 inch; breadth, 0.15; mouth, about 

 0.25 long, 0.09 wide. This and the preceding (Turris mconstans) have 

 many characters alike, and are both variable in similar directions, so 

 that at first they seemed varieties of one species, but the position of the 

 sinus and differences in size and form distinguish them. Two specimens 

 were found at Marysville Buttes by Mr. Watts." 



This species was found at University of California localities 

 1853 and 1856. It is easily distinguished from Turris incon- 

 stans by the absence of nodes and by the rounded form of its 

 whorls. Its sinus is not near the suture as Cooper states, but 

 near the middle of each whorl. It resembles Fusus diaboli Gabb 

 in geaeral form but is slightly more slender, its longitudinal ribs 

 are curved, and not straight like those of F. diaboli and its 

 whorls are rounder. 



Dimensions : Length 22mm ; width of body-whorl, 5mm. 



DRILLIA ULLREYANA Cooper 

 Mate 11, figure 8 



Drilla ullreyana. — Cooper, J. G., Catalogue of California Fossils, Bull. 

 4, California State Mining Bureau, p. 41. 1894. 



"General form oblong-rhombic; first three whorls smooth, conical; 

 fourth with seven strong knobs crossing it, and continuing on the six 

 following at regular intervals; crossed by about ten fine revolving rib- 

 lets above the middle, and four stronger ones below, increasing to about 

 thirty of uniform size on the body-whorl and canal. Mouth nearly half 

 of whole length, acute posteriorly, with a slight angle on upper third. 

 Canal tapering, straight, sinus deep behind angle. Length, about 0.6G 

 inch; breadth, 0.30; mouth and canal, 0.35 long, 0.12 wide. Marysville 

 Buttes, Mr. Watts; four similar specimens. 



The canal is long for a Drillia, but not more so than in D. raricostata 

 Gabb, which this much resembles, differing in having the knobs more 

 numerous, shorter, and broader. ' ' 



