130 The Ottawa Naturalist. [Tan. 



Metacarpal II is very short, being only about one-half the 

 ength of metacarpal III. There are only two phalanges to 

 digit II, an elongated one and a comparatively large, laterally 

 compressed, curved and sharply pointed ungual. In digit III 

 the first phalanx is short, the second long, and the distal one 

 claw-shaped but smaller than that of digit II. In the ungual 

 phalanx of digit II there is a decided claw-groove. The first 

 phalanx of digit II and the first and second of digit III have a 

 deep pit on each side of the distal end. In the corresponding 

 part of the metacarpals there is only a slight irregular depression. 



Four carpal bones are preserved between the ulna and 

 radius and the metacarpals, but they are slightly displaced. 

 One is roughly discoidal and larger than the others, which are 

 compressed ovoid in shape. The largest one occurs at the proxi- 

 mal end of metacarpal III, the other three lie together at the 

 distal end of the radius. The ulna and radius are solid except 

 for a small axial area of cancellous bone. 



As already mentioned, the elements of the manus follow 

 each other in regular succession and are apparently all in place 

 with none of the phalanges missing. The phalangeal formula 

 revealed is therefore probably the correct one. 



The figure accompanying this description shews the relative 

 size of the fore-limb and the scapula with the coracoid. The 

 limb is here shewn in lateral aspect, in a natural position below 

 its articulation with the scapula, and with the digits only slightly 

 curved. 



Attention is drawn to the extreme shortness of metacarpal II 

 and the elongation of the penultimate phalanx in each digit. 

 A similar lengthening of the corresponding phalanges is seen in 

 the manus of the small Jurassic Ornitholestes hermanni, Osborn,* 

 in which also there are two digits, a vestigial metacarpal IV, 

 and an enlarged ungual phalanx in digit II. 



The estimated length of this dinosaur, which, for the present, 

 is referred to the genus Deinodon, is between twenty-eight and 

 thirty feet. Why its front limbs were so diminutive is difficult 

 to explain. That they were of much use in feeding is improbable. 



The discoverer of this splendid specimen was Charles 

 Sternberg, Jr., who was one of the vertebrate palaeontological 

 field party of 1913. 



Measurements. Feet. Inches. 



Length of humerus I2f 



" ulna 6'. 



" radius 6$ 



" metacarpal II [\ 



* Bull. Am. Mu-. Nat. Hist;., New York, vol. xix, article xii, pp. 459-464, figs. 2 and 3, 



