612 
DE. HUNTHEE ON THE ANATOMY OF HATTEEIA. 
subcylindrical in the middle ; the transverse axes of the expanded extremities intersect 
each other at an angle of about 40°; the entire bone is somewhat longer than the ulna. 
The ulna and radius do not exhibit any peculiarity; the facet of the former for 
articulation with the humerus is small, not larger than that of the olecranon, which is a 
well-developed, oblong, tetrahedral bone. The distal extremities of the bones of the 
forearm are not in contact with each other. The carjpus is composed of ten bones, five 
in each series; most of them are broader on the inner (palmar) surface than on the 
outer. The ulna articulates with three : one ( pisiforme ) is, as it were, pushed out and 
attached to the outer side of the extremity of the ulna, where it forms a very conspicuous 
prominence for the attachment of the ligaments and muscles which will be mentioned 
subsequently ; the two others ( triquetrum and lunatum ) are the largest of all these bones, 
making up for the shortness of the ulna, which does not reach so far downwards as the 
radius. The radius articulates with two bones, which together may be regarded as an os 
naviculare ; the outer of them projects more than the other, and sometimes articulates 
with the fifth digit. The bones of the second series correspond to the metacarpals, that 
of the second digit ( capitatum ) being somewhat more prominent than the others. Vari- 
ations of this arrangement of the carpal bones do not appear to be scarce ; thus, for 
instance, the os lunatum has been found removed from the ulna, pushed between the two 
series. Of the metacarpals the third and fourth are longer, the first and fifth shorter, 
than, and the second as long as the two following phalanges together. The phalanges 
are two, three, four, five, and three in number, and the penultimate is never longer than 
the preceding (as, for instance, in Monitor). 
Muscles of the Fore Limb. 
Muscles of the humeral region and upper arm. — The MM. deltoideus and latissimus 
dorsi do not show any peculiarity ; the former arises only from the surface of the carti- 
laginous portion of the scapula. The mass of muscles nearest to the bone and passing 
over the humeral joint, homologous with the MM. supra- and infraspinatus et teretes, is 
only partially subdivided. All these muscles lift and approximate the limb to the trunk ; 
and this is done in a direction more or less backward, according to the degree in which 
the M. latissimus dorsi is brought into action. 
Two muscles take their origin from the bony arch formed by the transverse piece of 
the episternum and clavicle: — first, the portio clavicularis of the M.pectoralis major, which 
is elongate, hammer-shaped, its fibres converging into a very strong tendon, in advance 
of the middle of its outer margin, and inserted, as usual, into the tuberculum majus. 
Although its fibres are in perfect contiguity, and all tend to depress the limb towards 
the chest, they are so disposed that the anterior portion draws it forward, the posterior 
backward, and the middle vertically to the longitudinal axis of the body. The second 
muscle arising from the clavicle has no homologue in the fleshy part of Mammalia ; 
it is the claviculo-brachialis of Emys, and situated immediately below the portio cla- 
vicularis of the pectoralis major , flat, arises from the whole posterior side of the clavicle, 
