86 MR. A. SANDERS ON THE [Jail. 6, 



Gluteus maxima* (fig. 5, 01. Mx.) is more distinct from the rectus 

 than in L. belli, and still more so than in P.japonicum. It arises from 

 the whole length of the posterior apophysis of the ilium, and joins 

 the vastus externus at about the centre of the thigh. This is the 

 same as gluteus maximus in Iguana, but not in the Chameleon. 



Biceps femoris (fig. 5, B.F.) arises from near the posterior end of the 

 posterior apophysis of the ilium by means of a narrow tendon, and, 

 passing down the thigh, is inserted into the outer side of the fibula 

 a short distance beyond the head of the bone ; its tendon is crossed by 

 that of the peronaeus ; this corresponds to the ilio-peroneal in Iguana. 



Semimembranosus (figs. 5 & 6, Sm.) arises fleshy from the postero- 

 external angle of the ischium and from the ventral end of the ilio- 

 ischiatic ligament ; its belly forms an elongated cone, which becomes 

 at the distal half of the thigh a long thin tendon, which receives the 

 tendon of the pelvo-tibialis, and is inserted into the outer edge of the 

 head of the tibia, passing through the knee-joint on its way. _ In 

 this species the semimembranosus of L. belli and the principal 

 section of that muscle in P. japonicum appear to be absent ; but this 

 muscle would seem to represent that section of the semimembranosus 

 which in P.japonicum was inserted between the tibia and fibula, close 

 to the insertion of the pelvo-tibialis, and corresponds to the second 

 portion of the semimembranosus in Iguana. 



Semitendinosus (figs. 5 & 6, St.) arises immediately behind the 

 last, from the posterior part of the ilio-ischiatic ligament, extending 

 nearly as far as the posterior end of the ilium. It ends in a long thin 

 tendon, which is inserted into the external edge of the head of the 

 tibia close to the insertion of the pelvo-tibialis ; it also gives off two 

 supplementary tendons, one of which goes to the inner side of the 

 tibia, close to the insertion of the gracilis, the other goes down the 

 leg along the inner edge of the soleus ; this clearly corresponds to 

 the biceps in Iguana. I am still of opinion that the interpretation 

 of these three muscles is in the main correct. "With regard to their 

 origins they maintain the relations found in the human subject 

 (semimembranosus arising ventrad of the others) both in the present 

 specimen and in L. belli and P.japonicum, where, moreover, the two 

 latter muscles are inserted into the inner side of the head of the tibia. 

 With regard to the ilio-peroneal, both its origin and insertion appear 

 to me to agree very well with those points in the biceps ; and Prof. 

 Rolleston in the memoir above referred to remarks that " this muscle 

 is clearly one of the series made up of the biceps &c," which opinion 

 might perhaps justify me in adhering to my former interpretation. 



Gluteus medius (fig. 5, Gl. Md.) arises fleshy from the outer side 

 of the anterior two thirds of the ilium, covered by the gluteus 

 maximus, and is inserted into the outer and posterior side of the 

 femur for nearly half its extent beyond the head and behind the 

 origin of the vastus externus. 



Quadratus femoris (fig. 5, Q.F.) arises from the posterior point 

 of the ilium behind the biceps femoris and in front of the semitendi- 

 nosus ; it is inserted into the proximal end of the femur dorsad of the 

 insertion of the pyriformis. 



