382 



University of California Publications. [Geology 



The two specimens available, together with a large number 

 of other Triassie ichthyosaurian forms, were discovered in 1895 

 by the expedition to West Humboldt Range. The work of this 

 party was made possible through the generosity of Miss Annie M. 

 Alexander, who was herself the discoverer of the type specimen. 



Although the relationships of the form represented by these 

 specimens are not entirely clear, it has seemed best to publish 

 such information as is available, in the hope that this material 

 may assist in the interpretation of some of the fragmentary 

 saurian remains obtained elsewhere in Middle Triassie forma- 

 tions. The known material representing some of the older 

 marine Triassie saurians has thus far been very scanty, and the 

 specimens are widely scattered geographically. Only through 

 the publication of illustrations and detailed descriptions of these 

 widely scattered fragments, as they become available, will it be 

 possible to arrive at an understanding of the relationships of 

 the forms which they represent. 



DIAGNOSTIC CHAR ACT EES. 



PHALARODON FRAASI,'-' n. gen. ami sp. 

 Plate 40. 



Type specimen, no. 9853, Univ. Calif. Col. Vert. Palae., from 

 the Middle Triassie of south fork of American Canon, West 

 Humboldt Range, Nevada. Cotype, no. 9924, Univ. Calif. Col. 

 Vert. Palae., from the Middle Triassie of Fisher Canon, West 

 Humboldt Range, Nevada. 



Skull of ichthyosaurian type. Orbits moderately large, 

 superior nares situated a short distance anterior to the orbits. 

 Frontals exposed superiorly almost as far forward as the 

 posterior end of the superior narial openings. Nasals appar- 

 ently not extending far behind the anterior borders of the orbits, 

 and extending forward only a short distance in advance of the 

 superior narial openings. Angular element of mandible not 

 exposed anterior to the middle of the orbit. 



- 4>d\apa, a boss used to adorn head-gear of horses; odovs, a tooth. 

 The species is named in honor of Professor Eberhard Fraas, whose con- 

 tributions to our knowledge of the Ichthyosauria of Europe have been 

 greatly appreciated by the writer in his comparative studies of this group. 



