134 



MEMOIRS OF THE UNIVERSITY OF CALIFORNIA. 



(pi. 14), but in both limbs the phalangeal elements have been lost or scattered. 

 The propodial and epipodial segments are different from those of any other 

 known form. The humerus is considerably narrower medially than in Shas- 

 tasaurus, and is much more abbreviated and of very different form from that 

 in Merriamia or in Cymbospondylus. Excepting Cymbospondylus, this is the 

 only known Triassic type in which both epipodials of the anterior limb show 

 a median constriction. The ulna and radius have nearly the same form. In 

 both bones the median border is concave, and the lateral border is deeply 

 notched. Both elements are relatively much longer than in Skastasaurus, and 

 approach the length of the humerus. 



144a 



I44b 



145 



146 



Figs. 144a-146. Delphinosaurtis perrini Merriam. Elements of pelvis, X */2- 



Fig. 144a, ilium, posterior view; fig. 1446, ilium, median side; fig. 145, ischium; fig. 146, pubis. 



A proximal and a distal row of carpals, including three elements in each 

 row, are present. The proximal row is evidently complete, the same elements 

 appearing in both right and left limbs. The distal row may have included 

 more elements, though they are not represented in this specimen. In the first 

 row the radiale shows an anterior marginal notch as in the longipinnate ich- 

 thyosaurs. The intermedium is large and subquadrate in form in both right 

 and left limbs. The ulnare is relatively small and nearly circular in both 

 limbs. In the second row of carpals the third element from the anterior 

 border is almost immediately opposite the ulnare, and shows the same dimen- 

 sional relations to carpalia one and two that the ulnare shows in relation to 

 the radiale and intermedium. The noticeable reduction of the posterior ele- 

 ments in both rows of the carpus seems to indicate a reduction of the posterior 

 digits equaling or exceeding that in the tridigital manus of the genus Merriamia. 



The rounding of the margins of the carpal elements evidently indicates the 

 presence of considerable cartilage, and suggests a fairly high stage of special- 

 ization. 



The elements of the pelvis are all shown in the type specimen (pi. 17, and 

 text-figs. 144 to 146). An ischium and a pubis of similar character are also 



