1881. | 387 7 gees 
- Measurements of Vertebre. M. 
Width transverse process of atlas..........0....eee00s 010 
Vertical diameter neural and odontoid canal......... -. .015 
Length axis to odontoid process....... eS ee .033 
‘*  odontoid process....... Heididise Mesh iaeesean eae Ravens 007 
Diam. centrum behind | vertical { eats ne 
transverse......... abies we eee 0115 
Length of centrum of fifth cervical.............. soeeee 080 
a se seventh.......... Sa Reektsiettion asieh 017 
oe second dorsal.............-.00- .014 
Anteroposterior diameter of base of neural spine of 
second dorsal...........0. cece eeee siainen a wee ws 010 
Expanse of head and tubercle of first rib.............. -012 
Fore Limb.—The greater part of the blade of the scapula is lost. The 
neck is stout, and the coracoid is a short aliform process. The humerus is 
moderately robust, most so proximally. The greater tuberosity is a strong- 
ly incurved crest, with truncate summit, which is a little elevated above 
the plane of the head, from which it rises rather abruptly. The bicipital 
ridges are not strong nor prominent. The olecranar fossa is deeper than 
the coronoid fossa, and they communicate by perforation. The inner part 
of the condyle is the largest, and forms an acute angle with the interior 
epicondylar surface. The exterior part of the condyle is divided by an 
oblique angle of the surface separating an external bevelled band of the 
same, which narrows to extinction on the posterior side. As compared 
with the humerus of Hyrachyus eximius, that of Triplopus cubitalis is very 
similar, differing mainly in two points at the distal extremity. The 
olecranar fossa is smaller and is less excavated, and its lateral bounding 
ridges are of unequal elevation ; in 7. cubditalis they are equal. 
The ulna and radius are more than one-fourth longer than those of H. 
eximius. Although they are entirely distinct throughout, the ulna is quite 
slender anterior to the proximal third. The shaft is much more slender 
than that of Hyrachyus eximius. The olecranon is compressed, deep, and 
truncate behind. The distal epiphysis is remarkable for its length, being 
twice as long as that of the radius. The head of the radius is subequally 
divided by fossee, the external being the shallower. The inferior or ulnar 
facet is regularly and gently convex downwards, and is bounded behind 
by a roughened ridge, which, near the external border turns backwards to 
the humeral border. The shaft of the radius is robust and flattened. The 
carpal facet of the radius is contracted, and has three times the superficial 
area of that of the ulna. The scapholunar dividing ridge is present, but is 
very low. The scaphoid face is the more excavated, and then rolls back- 
wards, forming a very narrow posterior facet, which is narrower than that 
found in the species of Anchithertum. There is no distinct fossa on its 
inner or posterior border, as in many ungulates. The trapezium and 
scaphoid are the only bones of the carpus which are wanting. The latter 
PROC. AMER. PHILOS. SOC. xIx. 108. 2W. PRINTED MAY 16, 1881. 
