1890.] HELODERMA SUSPECTUM. 185 



other, more cord-like, extends dowu the leg, where it is in relation 

 with the soleus muscle. 



88. The Rectus femoris arises by two thoroughly distinct heads ; 

 one of these, and by far the slenderer, has its origin upon the pelvis, 

 just in front of the acetabulum, the tendon in this case being flat and 

 of some length. At about the middle of the thigh this head, which 

 has BOW become muscular, merges with the larger division of the 

 rectus, although both it and its tendon can be easily traced as far as 

 the patella. The larger head of the rectus arises from the pelvis 

 immediately over the acetabulum by a broad tendinous origin. 

 Soon becoming fleshy, the muscle ]iasses directly down the dorsal 

 aspect of the thigh, and, by a tendino-apoueurotic expansion, is in- 

 serted into the top of the patella, from which it is in turn reinserted 

 into the outer surface of the head of the tibia, through the interven- 

 tion of the ligamentum patellce. 



89. Gluteus iiuuvbnus. — Although here a distinct muscle, it has 

 praticallv the same origin and insertion as the larger of the two heads 

 of the rectus fehwris, with which it is almost indistinguishably fused. 

 It assists in covering the dorso-supcrficial aspect of the thigh pos- 

 terior to the latter, and in its action aids the rectus in extending the 

 leg upon the thigh, as in all Vertebrata where it is present. Upon 

 its underside, this muscle, in the lower part of its course, exhibits 

 a strong tendency to blend with the vastus exteruus, which lies be- 

 neath it. 



90. Peclineus. — By transversely dividing at their middles the 

 rectus femoris and the gluteus maxvnus and reflecting the mesial 

 stump, we bring to view the more deeply situate muscles of the thigh, 

 and the jjresent one can be easily examined. It is here found to be 

 of a triangular form, and arises from the ilium posterior to and above 

 the acetabulum ; it is also attached to the nether side of the tendon 

 of the (jluteus maximus, and more internally to the pubo-ischiadic 

 ligament. Largely carneous in its organization, its fibres pass down- 

 wards and forwards to the shaft of the femur, where they are inserted 

 upon a longitudinal line extending down the middle third of the same 

 at its postero-ventral aspect. 



9 1 . The Biceps femoris is a perfectly straight, subcylindrical muscle 

 of nearly uniform calibre throughout its length. Its single and only 

 head arises from the outer surface of the ilium, at its anterior third, 

 just behind and above the acetabulum, but posterior to the origin of 

 the peclineus. It is inserted on to the outer aspect of the shaft of the 

 fibula immediately below the head of the bone. At its origin it is 

 fleshy, but it is inserted by a comparatively strong tendon, as is 

 quite commonly the case in Lizards. Sanders found this muscle 

 arising from the posterior end of the ilium in Liolepis ; while 

 Hoflmann, from his description of this muscle, seems to think that 

 this is the only origin it can have (Bronn's ' Klassen,' loc. cit. 

 pp. 644, 645). 



92. Adductor hrevis.- — This is one of the smallest and at the same 

 time one of the most deeply situated muscles of the thigh. In some 

 respects it seems to correspond with either one or the other of the 



