C. W. Gilmore — New Species of Baptanodon. 197 



strong trochanteric ridge which is wholly confined to the proxi- 

 mal half of the shaft. 



The radixis and ulna, particularly the former, are closely 

 articulated with the humerus. In general form and size they 

 resemble very closely the corresponding bones of B. rnarshi. 



The pisiform in B. reedi is more elongate than circular in 

 form and articulates completely with the humerus. In these 

 respects it approaches the conditions found in the paddle of 

 the closely allied form Ophthalmosaurus ieenicus* although 



Fig. 2. Eight pectoral extremity of Ojjhthalmosaurus icenicus Seeley, 

 seen from above. One-fourth natural size. H, humerus ; E, radius ; U, ulna ; 

 P, pisiform. Paratype. (After Seeley.) 



a comparison of figures 1 and 2 shows the elements in the 

 latter genius to be more angular in their general outlines. 



The ulnare appears more elongated than in B. rnarshi, and 

 the intermedium more angular than those observed in other 

 specimens. 



The other elements of the paddle are more or less rounded 

 disks and a description of them would hardly add anything to 

 our understanding of this form. 



The writer considers the paddle of B. reedi as the most 

 highly specialized limb yet found among the American Ichthyo- 

 saurians. This is shown by the broadly expanded humerus, 

 which articulates closely and completely with the radius, ulna 

 and pisiform. 



*H. G. Seeley, Quart. Jour. Geol. Soc. of London, vol. xxx, pp. 696-707, 

 1874. 



