16 
H. ST. J. BROOKS ON THE 
The other portion has remained on the foot, and is represented by the first belly 
of the extensor brevis digitorum. 
The metatarsal heads of the short extensor are represented by some deeply 
placed slips of the extensor brevis, which were first described by Rucz. These slips 
vary greatly in their attachment. 
Fig. 
Fig. 
Fig. 
EXPLANATION OF PLATES. 
The following letters have the same signification In all the figures :— 
ab.h.l., Extensor ossis metatarsi hallucis. 
ab.p.l., Extensor ossis metacarpi pollicis. 
ex.b. 1 to 5, Extensor brevis digitorum, 1 to 5. 
ex.c.d.. Extensor communis digitorum. 
ex.c.u., Extensor carpi ulnaris. 
ex.m.d., Extensor minimi digiti. 
ol., Olecranon process of ulna. 
p.b., Peroneus brevis. 
p.i.n., Posterior interosseous nerve. 
p.l., Peroneus longus. 
t., Triceps. 
u.n., Ulnar nerve. 
. 1—Leg of Menobranchus. (5) ext. 1., ext. 2, portions of quadriceps extensor which are continuous 
with the intermediate and tibial sectors, 7.s. andt.s. f.s., fibular sector. e.p.m., peroneal nerve. 
e.b.d. 2 to 5, extensor brevis digitorum. 
external condyle of humerus. 
ig. 2.—Hand of Menobranchus. (5) m.sp., musculo-spiral nerve. .a., “nerve to anconeus.” .¢., 
U.8., 1.8., and 7.s., ulnar, intermediate, and radial sectors. ep.a., 
epitrochleo-anconeous. ex.b.d.m., extensor brevis digitorum manus. 
ic. 3.—Deep dissection of hand of Varanus. (24) The extensor carpi ulnaris is cut short and fixed by a 
hook, and its tendon, ex.c.w., is seen to give slips to the palmar surface of the carpus and to the 
fifth and fourth metacarpal bones. p., pisiform bone. 
. 4,—Forearm of Varanus viewed from the ulnar side. (2) ep.a., epitrochleo-anconeus. /f.c.w., flexor 
carpi ulnaris. abd.*, abductor minimi digiti. The tendon of the extensor carpi ulnaris (under 
which a pin has been placed) is shown passing into the palm under cover of this muscle. 
5.—A dissection of the forearm of Ornithorhynchus, showing the deep position of the extensor minimi 
digiti. (5) The extensor carpi ulnaris, ew.c.u., has been reflected. e.c., external condyle. 4., 
anconeus. ez. 1, 2, and 3, extensor pollicis, indicis et medii. ew.c.7., extensor carpi radialis 
brevior. 
6.—Forearm of Ornithorhynchus. 
( 
24). m.sp., musculo-spiral nerve. 
7.—Leg of Ornithorhynchus. (2). jf, “shovel-shaped” process of fibula. p., patella. 1 and 2, 
branches of the peroneal nerve to peroneus longus and brevis. a.cr., branch of anterior crural 
nerve supplying the two portions of tibialis anticus, ta. and f.a..  e.b.d., extensor brevis 
digitorum. 
