THE NAUTILUS. 71 



ably eight, two apical whorls being lost, rounded on sides; 

 suture linear, impressed. Surface marked by numerous, slightly 

 curved longitudinal ribs, about twenty-six to a volution; these 

 are more prominent near upper suture of the whorl and become 

 very indistinct at the lower suture ; very fine striae cover both 

 ribs and interspaces, running parallel with ribs ; ribs and inter- 

 spaces crossed alike by numerous shapely elevated revolving 

 threads, running parallel to suture. These produce a small 

 node at each crossing of the longitudinal rib one-quarter of the 

 way down on the lowest whorl, one-third down on the second, 

 one-half down on the third, and the entire way down on the 

 remaining whorls. Aperture, sub-circular ; inner margin some- 

 what thickened and curved. 



Dimensions (less several apical whorls). Alt., 16 mm.; lat., 

 7 mm.; alt. of body whorl, 13 mm.; alt. of aperture, 4^ mm. 



Notes. Named in honor of Dr. John C. Branner. 



Type. Museum, Stanford University, California. 



Locality. One mile north, 20° west of Tesla and Corral 

 Hollow, Tesla Quadrangle. 



Horizon. Middle Chico, upper Cretaceous. 

 ( To be continued) 



NOTES. 



Fossil Chitons. In working over some fossil shells from the 

 Pleistocene strata of Deadman's Island, San Pedro, California, 

 I find that I have three species which are not listed by Arnold 

 in his "Paleontology and Stratigraphy of the Pliocene and 

 Pleistocene of San Pedro." 



Katherina tunicata Sby. One perfect anterior valve. 



Jschnochiton conspicuns Cpr. One perfect posterior valve. 



Mopalia hindsii (Sby. ) Rve. One central valve in good con- 

 dition. 



These were identified by comparing with recent specimens. 

 Ischnochiton conspicvus is found living in this vicinity and has 

 been reported fossil from the Pleistocene at Signal Hill, Long 

 Beach, by Mr. T. S. Oldroyd. (Nautilus, vol. 28, page 80.) 



