312 



University of California Publications. [Geology 



MOEPHNUS WOODWARDI, n. sp.s 



Type specimen no. 12787, Univ. Calif. Col. Vert. Palae. 

 Tarsometatarsus. Resembling Aquila in general but thirty per 

 cent longer ; shaft narrower, ligamentous bridge shorter ; anterior 

 proximal depression shallower and less defined ; papilla of tibialis 

 anticus placed much higher on the shaft; ridges of the hypo- 

 tarsus less produced ; foot narrower and trochleae smaller. 



This species is based on a single perfect specimen excavated 

 at Rancho La Brea by the author. It was added to the Uni- 

 versity collection on account of its uniqueness. The bird repre- 

 sented was evidently an adult, since the intermuscular lines, the 

 tubercles and the foramina show complete ossification. 



The establishment of this species was delayed for some time 

 by the absence of any first-hand impression of the existing 

 Thrasa'etus Jtarpya. It seemed scarcely probable from descrip- 

 tions of Tltrasaetus in the flesh that there could be any great 

 degree of similarity between the two forms, yet the linear 

 dimension of the tarsometatarsus of Thrasa'etus, the only 

 measurement available, corresponded very closely with the same 

 dimension of the fossil form. The splendid cast of Thrasa'etus 

 sent by Dr. Smith- Woodward showed at a glance the enormous 

 difference that separates the two species. The Rancho La Brea 

 specimen exceeds by ten millimeters the length of the cast, and 

 yet it has but little more than half the transverse diameter of 

 shaft. In its general contours Thrasa'etus appears more as a 

 gigantic Haliaetus. The fossil form on the other hand suggests 

 an extremely elongate Aquila. 



The differences between Morphnus and Geranoaetus as dis- 

 played by the tarsometatarsus are slight, and are limited so far 

 as is noticeable to the head region of the bone. In Geranoaetus 

 the anterior face in this region resembles Haliaetus in the great 

 length of the supratendinal bridge. The crest marking its 

 external end falls almost in the center of the bone as in Haliae- 

 tus. This face of the bone is also less abruptly excavated — a 

 character distinguishing Haliaetus. A further distinguishing 



3 This form is given its specific name in honor of Dr. A. Smith- Wood- 

 ward of the British Museum of Natural History. 



