186/.] MYOLOGY OF IGUANA TUBERCULATA. 79 J 



by the spine of the pubis, to the ischiatic symphysis. It is inserted 

 into the summit ot the trochanter below, and superficial to, the other 

 two portions (fig. 1/, Pc. J). 



(2) The second part (fig. 17, Pc. 2) arises from the down-turned 

 lip ot the pubis, from the acetabulum to the symphysis. It is in- 

 serted immediately beneath the preceding portion. 



(3) The third part (fig. 1 7, Pc. 3) arises from the symphysis 

 pubis, backwards to the middle of the obturator foramen At the 

 posterior end of its origin the obturator externus is superficial to it 

 and overlaps It It is inserted into the summit of the trochanter 

 immediately behind the second part. 



The adductor magnus (figs. 14 &'l7, A.) is a rather large muscle 

 which arises, l)y strong tendinous fibres, from the anterior part of 

 the strong tendinous arch before mentioned which ends in front at 

 the pubic spine. It is inserted into the inner side of the shaft of 

 tlie temur (tor about the second and third fifths of its vertical ex- 

 tent) between the vastus externus and the vastus internus 



llectusfenu>risiS^^^.\\\A,\&S,\7,n.F.). This muscle arises, 

 by a very s rong and rather broad tendon, from the ventral side of 

 the acetabulum. It blends with the other extensors of the le- and 

 with the aponeurosis of insertion of the gluteus maximus * 



Vastus internus. A rather small muscle (figs. 14 & 17 V I\ 

 arising from the inside of the shaft of the femur, about as high as"the 

 bottom of the uppermost third of the insertion of the adductor; 

 below it blends with the crureus and other extensors of the leer 



Vastm externus (fig. 15, V. Ex.). This is exceedingly small.* and 

 so intimately connected with the crureus as scarcely to admit of de- 

 bnition. It arises from the lowest two-fifths of the postero-external 

 surface of the shaft of the femur, and is inserted with the rest of the 

 extensor mass. 



Cmm.* (figs 16 & 17, C). This muscle is so intimately con- 

 nected with the last as to be separable from it only with great diffi- 

 culty. It arises from the front of the femur, its origin extendins 

 up near to the head of the bone. It is inserted into the patella 

 along with the rest of the extensor muscular mass. At its summit 

 It IS, in part, continuous with the fourth portion of the iliacus 



Gluteus maximus {1). A muscular layer, which may perhaps re- 

 present the gluteus maximus of mammals*, arises by a very strono- 

 tendinous fascia from the outer side and upper margin of the ilium" 

 It covers the antero-external side of the thigh, becomes intimately 

 united with the rectus femoris. and is inserted by aponeurosis into 

 the outer surface of the vastus externus (figs. 13. 14 15 & ifi 

 G.Mx.). ^ LKj, 



The gluteus medius arises from the outer surface of the ilium be 

 tween the origins of the gluteus maximus and ilio-peroneal. It' is a 

 small muscle, and is inserted into the outer side of the upper part 



*l am very doubtful as to ^4>ether this muscle and the next are v^^Wj glufei ■ 

 but the cond, ion of these nmscles m Echidna inclines me to name them so pro^ 

 visionally at least (see Trans. Linn. Hoc. vol. xxv. ISCfi, p. 391, and pi. 5.3 fie 2 

 6-. nix. and G. md.). x > i j. "g, a. 



