236 Transactions.— Zoology. 
ischii, and uncinate process and anterior border of the pubis. It is closely 
connected with the gracilis. In Iguana Mivart calls this broad sheet 
sartorius; Sanders, in Platydactylus, calls the broad sheet sartorius, and 
the slender gracilis. The fibres of this broad mass converge and pass 
down the inner side of the thigh to be inserted into the posterior part of 
the tibia just below the head. Günther calls this sheet a prolongation of 
the M. obliquus abdominis externus. 
À strong broad ligament reaches from the uncinate pubie proeess to the 
symphysis ossium ischii. From the under-surface of this ligament, about its 
middle-third, arises a narrow muscle which is inserted into the middle of 
posterior surface ofthe femur. It adducts the leg. It is probably biceps 
femoris ; but the distinctions of some of these muscles are difficult to make 
out. The semi-tendinosus and semi-membranosus (?) arise from the tuber 
ischii, and by a branch from two or more caudal vertebre, and are inserted 
into the tibia. These muscles flex the limb, or if that be fixed assist in 
moving the tail. 
M. obturator externus arises broadly from whole outer face of pubis and 
ischium, lies in contact with the pubis and ischium, closely covers in much 
of the hip-joint, and is inserted by a flattened tendon into inner tuberosity 
of the femur and digital fossa. 
Obturator internus arises from ramus and body of pubis, from symphysis 
pubis, and from uncinate process of pubis, from outer surface of tuber 
ischii and ramus ischii, and from membrane lining obturator foramen. 
Ischio-caudal arises by a narrow tendon from the tuber ischii, and is attached 
to the hemapophyses of six or seven caudal vertebra. Internally, it lies 
against its fellow of the other side, the arms lying between them near their 
origins. Externally, both are covered by the femoro-caudal, which arises 
from the sides of the hemapophyses of several vertebrg ; the thickest fibres 
arise from the vertebrz nearest the sacrum; these form a round thick mass. 
The insertion is very curious. The broad thin layer of fibres coming from 
the more distant vertebre unite to form a strong glistening tendon which 
passes under the ischio-caudal ligament to the inside of the upper end of 
the femur. About one-third of an inch from this insertion it gives off a 
very delicate long branch, which runs down the whole length of the femur 
in close proximity to the great ischiatic nerve, which it very closely 
resembles ; it traverses the popliteal space, and is inserted into the back of 
the fibula. The long slender tendon helps to flex the leg upon the thigh, 
and acts also on the popliteal fascia. The other tendon would draw the leg 
backward or move the tail. Günther thinks it would also rotate the limb 
outwards ; but this perhaps is not the case, because the tendon at insertion 
80 grasps the leg as (possibly) to neutralize any such effort. 
