1915] 



Clark: Fauna of the San Pablo Group 



503 



This species resembles in outline Murex (Ocinebra) lurida var. 

 aspera Baird and in a former paper was listed as such by the writer 

 ("The Neocene Section of Kirker Pass, Univ. of Calif. Publ. Bull. 

 Dept. Geol., vol. 7, no. 4, pp. 17-60, 1912). It differs from that species 

 in the character of the revolving ribbing. On M. lurida var. a,spera 

 the revolving ribbing is not obsolete just below the sutures, as in the 

 case of M. selbyensis. Also the number of revolving ribs is greater on 

 the former than on the latter. The canal on the latter is more slender 

 and a little longer than that on the former. 



Dimensions. — Type specimen: height, 35 mm.; greatest diameter 

 of body whorl, 23 mm. 



Occurrence. — Lower San Pablo Group, associated with Astrodapsis 

 tumidus, subsp. cierboensis, Chrysodomus pabloensis, n. sp., Tivela 

 diabloensis, n. sp., etc., University of California localities 102, 409, 410, 

 525, etc. 



CANCELLAEIA PABLOENSIS, n. sp. 

 Plate 68, figures 9 and 31 

 Shell ovate, thick ; body whorl large ; spire moderately low. Num- 

 ber of whorls to spire three or four ; suture appressed ; body whorl 

 with fifteen or sixteen pointed nodes a little below the suture ; this 

 gives the whorl the appearance of being angulated or obscurely tabu- 

 lated; whorls of spire not nodose. Surface of shell sculptured by 

 medium fine revolving ribs, the interspaces between which are much 

 narrower than the tops of the ribs. On the bocly whorl there are 

 about thirty of the revolving ribs, while on the whorls of the spire 

 there are only three or four. Canal short, very slightly twisted ; outer 

 lip sharp ; inner lip callused. Columella with two fairly strong pli- 

 cations. 



Dimensions. — Type specimen : height, about 34 mm. ; height of body 

 whorl, about 29 mm. ; maximum width of body whorl, 27 mm. 



Occurrence. — The type specimen was found in the San Pablo 

 Group of Napa County, west of Will's ranch, Carneros Creek, by Mr. 

 S. TL Gester and Mr. Reginald Stoner. Here it was associated with 

 Tivela gabbi, n. sp., Natica arnoldi, n. sp., and Mulinia densata Con- 

 rad, also found on the south side of Mount Diablo and on Rocky Ridge 

 to the south of Walnut Creek. Both of these last localities are in the 

 Upper San Pablo, University of California localities 480 and 1942 ; 

 here the species is associated with the same fauna as in Napa County. 



