Pectoral Fin of Eusthenopteron. 



475 



does not entirely confirm the theory of Gegonbaur, according 

 to which the tetrapod limb is derived from a reduced uniserial 

 archipteryo-ium (comp. G-egenbaur, 1898, p. 520), bnt never- 

 theless it is more in conformity with this theory than with 

 the other (also advocated by Watson), which takes a l-educo I 

 biserial archipterygium for the base of the tetrapod limb. 



Fig. -2. 



ax. 



The internal skeleton of the Pectoral Fin of Eusthenopteron, showing 

 homologies with, the tetrapod limb. Nat. size. 



hu., humerus ; u., ulna ; r., radius; ul, ulnare ; p., pisiform ; i 

 distal carpalia ; I- V., digits ; ax., axis of the tetrapod li 



ca., three 

 limb. 



Tn conclusion, I desire to express my thanks to Dr. Smith 

 Woodward for the loan of the new preparation and for 

 valuable help. 



Literature. 



J. F. Whiteaves. " Illustrations of the Fossil Fishes of the Devonian 



Rocks of Canada," in Trans. I!oy. Soc. Canada, vol. vi. 1889, 



p. 77 seq. (on Eusthenopteron, p. 78 seq.~). 

 I\. H. Traquair. "Notes on the Devonian Fishes of Scaumenac 



1 Jay and Campelltown in Canada," in Geol. Mag. vol. vii. 1890, 



p. 15 seq. (on Eusthenopteron, p. 18 seq.). 



