120 



University of California Publications. 



[Geology 



ate, with serrated or comb-like edge. They vary considerably in 

 breadth, but they must belong' to this same species. 



Family DASYATIDiE. 

 Genus Urolophus Miiller & Henle. 



25. Urolophus halleri Cooper (?). 



(Arnold, Pliocene and Pleistocene, Cal. p. 346, San Pedro.) 



A spine from the tail of a sting ray was found by Dr. Ralph 

 Arnold in Pleistocene deposits at San Pedro. According to Dr. 

 Gilbert it is not distinguishable from the common living species 

 of the region, Uroloplnis halleri. 



Family HOLOPTYCIIIDE. 



Genus Holoptychus ilgassiz. 



26. Holoptychus species. (Holoptychius of authors.) 



Three fragments of Crossopterygian scales, much like those of 

 Holoptchyus, are found in Triassic Rocks at Bear Cove in Shasta 

 County. The largest of these is about an inch in diameter, with 

 coarse branching striae or wrinkles. The ridges are closer to- 

 gether and cover more space than the European species, Holopty- 

 ch us flerningi. 



Family CHIROCENTRIDiE. 



Genus Xenesthes Jordan, new genus. 



27. Xencstlics velox Jordan, new species. 



In a rock of Triassic age are the remains of a skull of a fish, 

 apparently belonging to the primitive family of Chirocentridce. 



Number 9,098, University of California collection, represents 

 a premaxillary bone over seven inches long. It is armed on its 

 anterior end with a single row of conical bluntish teeth, each with 

 a striated and beveled apex, unequal in size and some of them 

 broken out. The fourteen teeth visible occupy less than one- 

 fourth the length of the bone. Behind the point where the tooth- 

 row disappears in the matrix there is a broad band of blunt pyra- 

 midal prichles of much smaller size on the outer surface of the 

 bone. They are close-set almost so as to form a shagreen. There 



