NO. 2120. THE FORE LIMB OF ALLOSAURUS FRAGILIS—OILMORE. 505 



The inner surface of the greater part of the blade is flattened antero- 

 posteriorly while the outer surface, excepting the upper fourth, is 

 rounded in this direction. The articular end being expanded both 

 antero-posteriorly and transversely is heavy, especially on the pos- 

 terior half, which has a maximum thickness immediately above the 

 glenoid fossa of 58 mm. The scapula unites with the coracoid by a 

 straight suture that bisects the glenoid fossa and is terminated above 

 by a deep notch between the scapula and coracoid on the anterior 

 border. In this individual both scapulae are firmly coossified with 

 their respective coracoids. The scapula of this specimen appears to 

 agree in all particulars with the one found with the mounted skeleton 

 of Allosaurus ui the American Museum of Natural History, and it also 

 shows that the limb described by WOliston should be referred to this 

 genus .^ In this connection it is of interest to know that the Cerato- 

 saurus scapula which formed the basis for the illustration of this bone 

 in the so-caUed fore limb of Allosaurus is now in the United States 

 National Museum collections (fig. 1). I have recently examuied the 

 bone and find that its upper extremity is incomplete, so that it is not 

 positively known whether this blade has a nonexpanded end as repre- 

 sented by Marsh or whether it was expanded as in Allosaurus. It 

 differs, however, from Allosaurus m. having a thumer and wider shaft 

 and a more abrupt backward curve of the heavy posterior border just 

 above the glenoid fossa. Both inner and outer surfaces of the lower 

 three-fourths of the shaft in Allosaurus are rounded. Both of these 

 specimens came from the famous quarry No. 1 near Canon City, 

 Fremont County, Colorado. 



Measurements of scapula. 



mm. 



Greatest length of right scapula and coracoid, measured along outside curve. . . 795 



Greatest length of right scapula 652 



Greatest breadth of right scapula. 175 



Greatest breadth of blade, upper end 2 ^45 



Least breadth of blade 52 



Greatest expanse of glenoid fossa 71 



Coracoid. — The coracoid in Allosaurus is quadrangular in outline, 

 the infero-superior measurement exceeding the antero-posterior diam- 

 eter. The outer surface is convex in aU directions, the inner decid- 

 edly concave antero-posteriorly. There is a broad notch on the 

 inferior border. 



The coracoid is pierced by the usual foramen, which runs diago- 

 nally through the bone, the external exit being larger than the inter- 

 nal. This foramen is entirely inclosed (fig. 2), not a notch as shown 

 m. Marsh's figure of the coracoid (fig. 1). The superior border pre- 



> Ainer. Joum. Sci., vol. 11, 1901, p. 113. « Estimated. 



