014 
DR. GUNTHER ON THE ANATOMY OE HATTERIA. 
extreme phalanges of the fingers, without a trace of MM. luinbricales ; a M. flexor digi- 
torum sublimis appears to be represented in a rudimental condition by a flat and thin 
muscle, which takes its origin from the fascia covering the lower part of th e profundus, 
and chiefly from a ligament extended between the os pisiforme and os naviculare ; it is 
fan-like, expanded over the palm, and at the base of each digit the fibres diverge for the 
passage of the tendons of the profundus ; for this reason I am inclined to regard this 
muscle as a rudimental l. d. sublimis rather than as a muscular fascia palmaris. A 
strong aponeurotic palmar fascia is not developed. Secondly, the flexor carpi radialis 
and M. pronator teres arise united into one muscle, the latter becoming distinct towards 
its insertion on the middle of the radius, and being entirely covered by the former, which, 
as usual, descends to the end of the radius and to the carpus. Thirdly, the flexor carpi 
ulnaris, subdivided by a broad aponeurosis along the middle of its interior ; a part of it 
passes the carpus and forms an abductor digiti minimi. 
The extensor muscles arise chiefly from the outer condyle of the humerus and the 
outer surface of the bones of the lower arm ; they are less powerful than the flexors, 
and more intimately connected with each other by intervening tissue, which disappears 
entirely towards their origins ; so that their separation is artificial for a part of their length. 
Six can be distinguished, viz. : — The M. supinator longus and the extensor carpi radialis 
brevis and longus ; they are slender, running parallel to each other, and inserted more 
distinctly into the carpal bones than into the metacarpals. The extensor digitorum 
communis is the most powerful muscle of this region, and in its lower part divided 
into two portions, the longer of which terminates in an aponeurosis attached to the 
metacarpal bones, whilst the shorter coalesces with the distal portion of the extensor 
carpi radialis brevis. Covered by the proximal portion of the muscle last described, and 
situated inwards of the olecranon, is a very distinct oblique muscle, arising from the 
condylus internus humeri, and attaching itself to the outer surface of the olecranal part 
of the ulna; it occupies exactly the position of the Anconceus guartus, and may be 
regarded as such, or as an Extensor carpus ulnaris (which otherwise could not be 
accounted for). Finally, the muscles which in Man are divided into the abductor and 
extensors of the thumb, form in Hatteria one flat layer covered by the Extensor digitorum 
communis , arising from the distal half of the ulna, and spreading over the bones of the 
carpus, to which they are attached ; the fibres nearest to the radial margin are collected 
into a tendon which is inserted at the metacarpal bone of the thumb. 
There is no ligamentum osseum between ulna and radius ; it is replaced by a strong 
muscle, the fibres of which are transverse, either vertical to the longitudinal axis of the 
arm, or obliquely descending from the ulna to the radius. 
Of the muscles of the hand , besides those mentioned above and the interossei , one 
remains to be noticed, lying below the flexor digitorum communis on the metacarpal 
bones ; it arises from the second series of carpal bones, its fibres diverging chiefly from the 
carpal bone of the fourth digit (os hamatum) to the base of the proximal phalanges 
of the digits ; it essentially assists in adduction and flexion of the digits. 
