500 
Proceedings of fJie Royal Irish Acade))}y. 
femoris. The gracilis is very wide ; the rectus has two heads as usual, 
the curved one being made of mixed fleshy and tendinous fibres ; the 
whole extensor mass on the front of the thigh, including the rectus, was 
indivisible and equalled the psoadiliac in size ; the vastus internus was 
the only part slightly separable. 
The popliteus occupied the upper half of the tibia, arising as usual. 
The gastrocnemius had two heads, an internal, double the popliteus in 
size, and an external, a little smaller, with which the plantaris was in- 
separably joined ; there was no soleus. The tendon of the gastro- 
cnemius was attached to the heel, that of the plantaris ran into the 
plantar fascia. There was a single tibio-fibular flexor muscle for the 
toes which gave ofl" 4 tendons, and equalled the external gastro- 
cnemius in size. The tibialis posticus was very small, and tibio-scaphoid 
in attachments. The flexor brevis was represented by a few fibres in 
the plantar fascia. The tibialis anticus was double; one part arose 
from the tibia, and was inserted into the 1st metatarsal; the other, 
only half as large, arose from the outer condyle of the femur, by a com- 
mon origin with the extensor longus digitorum, and was inserted far- 
ther forwards. 
The synovial membrane of the knee joint made a transversely 
vertical partition on the plane of this tendon, and the anterior part 
of the cavity only communicated with the posterior by an opening 
behind and external to it; this occurs in other animals with a 
femoral tendon, when that tendon arises anteriorly, as in the Kyl-ghau, 
Axis, &c., but not when the tendon is very much lateralized, as in Car- 
nivora; then it may not pass through the joint cavity at all. 
The extensor hallucis arose from the upper point of trisection of the 
fibula, and was inserted into the base of the third metacarpal bone ; it is 
very distinct, but very small ; the extensor digitorum longus arose from 
the front of the condyle of femur along with the second tibialis anticus, 
and was inserted by a fascial expansion into the toes, the slip to the 4th 
toe being very weak. This muscle equals the second tibialis anticus 
in size, and is a little larger than the corresponding fore-limb-muscle. 
The peroneus longus was as usual; the second peroneus is a p. quinti 
arising from the fibula to be inserted into the outer surface of the 
4th toe. 
The interossei are smaller in the foot than in the hand, they are as 
follows: Abductor indicis. Adductor indicis. Abductor medii (tibialis), 
Abductor medii (fibularis). Adductor annularis, Abductor annularis, 
Adductor minimi and Abductor minimi ; to these is superadded a long 
adductor minimi digiti, from the ectocuneiform to the inner side of the 
first phalanx of minimus. (Plate XXVIIL, Fig. 4.) 
