UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 5, No. 5, pp. 71-79, Pis. 8-9 ANDREW C. LAWSON, Editor 



PRELIMINARY NOTE ON A NEW MARINE 

 REPTILE PROM THE MIDDLE 

 TRIASSIC OF NEVADA. 



BY 



John C. Merriam. 



In the summer of 1902 a joint expedition from Stanford 

 University and the University of California visited the Middle 

 Triassic outcrops of the West Humboldt range in Nevada to ex- 

 plore these beds for palaeontological material. Mr. V. C. Osmont, 

 who represented the University of California, devoted himself to 

 the search for vertebrate remains. He was fortunate in obtaining 

 a number of reptilian specimens, which furnished the first satis- 

 factory information concerning the nature of the marine saurians 

 known to occur there. 1 The greater part of the material obtained 

 by Mr. Osmont consisted of remains referable to ichthyosaurian 

 forms. 2 Associated with the ichthyosaurs is a single specimen 

 representing a form which does not closely resemble any de- 

 scribed reptilian type. This specimen consists of several anterior 

 cervical vertebrae, the greater part of a mandible with the denti- 

 tion, and the inferior portion of the cranium. In collections ob- 

 tained later from the same locality there are several fragmentary 

 specimens showing similar structure. The peculiar features of 

 this specimen separate it from other forms as a distinct genus and 

 species, possessing the following characters. 



1 J. Leidy, Proc. Philad. Acad. Sc., Vol. 20, p. 177; and J. C. Merriam, 

 Bull. Dept. Geol. Univ. Calif., Vol. 3, p. 107. 



• A Primitive Ichthyosaurian Limb front the Middle Triassic of Nevada. 

 J. C. Merriam, Bull. Dept. Geol. Univ. Calif., Vol. 4, p. 33. 



