532 ON THE SACRAL PLEXUS AND SACRAL VERTEBRA OF LIZARDS. 



24. Branch to gracilis. 



25. Branch to semimembranosus. 



26. Another branch to semimembranosus. 



27. Branch to semitendinosus. 



28. Branch to pyriformis. 



29. Intersacral nerve. 



29a. Second intersacral (in Cat). 



30. First postsacral nerve. 



31. Branch to penis. 



32. Commissure or commissures between 29 and 30. 



33. Sciatic nerve. 



34. Branches to gluteus maximus and medius. 



35. Branch to ilio-peroneal. 



36. Branches to femoro -caudal. 



36 a. Extra branch to femoro-caudal. 



37. Internal popliteal nerve. 



38. External popliteal nerve. 



39 and 40. Divisions of external popliteal nerve. 



41. Branches to transversus perinei and sphincter cloaca. 

 41 a. Branch connecting first and second postsacral nerves. 



42. Second postsacral nerve, ending in branches to mucous membrane of cloaca and to skin. 



43. Branch to cloaca. 



44. Branch to femoro-caudal, and extending down to the tail. 



45. Branches to skin and lateral caudal muscles. 



46. Branch in Agama {i.e. in fig. 5, Plate LXVL), extending postaxiad from the third presacral 



nerve to the lumbo-sacral nerve. 



Vertebra. 



A. Most preaxial vertebra articulating with ilium. 



B. Second (or more postaxial) vertebra articulating with ilium. 



I. Vertebra preaxiad to A. 



II, III, IV, and V. Vertebra? successively more and more preaxial. 



I*. Vertebra postaxial to the more postaxial vertebra articulating with ilium, or to the only vertebra 



which so articulates. 

 II*, III*, and IV*. Vertebrae successively more and more postaxial. 



