504 



PROCEEBlTslOB OF THE NATIONAL MVSEVM. 



VOL. 49. 



There are three digits, which have the phalangial formula of 2, 3, 



and 4. Digit one is the heaviest of the series and mtc. Ill is reduced. 



Scapula. — Both scapulae are preserved with the present specunen, 



the right being perfect, 

 as shown in figure 2, with 

 the exception of a small 

 portion of the upper an- 

 terior corner of the blade 

 which is missing. The 

 left scapula was injured 

 in life and the subsequent 

 healing produced great 

 deformation of the bone. 

 This pathologic condi- 

 tion caused a widening 

 of the blade that would 

 be entirely misleading as 

 to its true form had not 

 the opposite scapula 

 been present. The scap- 

 ula of Allosaurus is dis- 

 tinctive on account of its 

 bird-like form, as has pre- 

 viously been pointed out 

 byWilliston.^ The shaft 

 is exceptionally long and 

 slender, bemg nearly of 

 equal width throughout 

 except the uppermost or 

 distal extremity, which 

 is perceptibly widened. 

 This expansion is about 

 equal in fore and aft 

 direction. The upper 

 third is flattened and 

 thin, while more proxi- 

 mally the shaft is trihe- 

 dral in cross-section, the 

 anterior border being 

 sharp, the posterior one 

 rounded. Longitudin- 

 ally the external surface 

 is convex, though nearly straight in its middle portion, a shape that 

 probably conformed closely with the convex c urve of the body cavity. 



1 Amer. Journ. Sci., vol. 11, 1901, p. 113. 



Fig. 2.— Right foee limb and foot of Allosaurus fragilis 

 Marsh. Cat. No. 4734, U.S.N. M. J n at. size. Lateral 

 VIEW, Cj.CARPALE TWO; Cor, CORACOID; h, humerus; in, inter- 

 medium; r, radius; ra, eadlvle; Sc, scapula; u, ulna; I, II, 



AND III, digits one, TWO, AND THREE. THE POSITION OF THE 

 MISSING tJLNAEE IS INDICATED BY DOTTED LINES. 



