Mr Appleton, The Gluteal Region of Tarsius spectrum 469 



the muscle. It appears from the description of Burmeister that his 

 "deep" or "second pyriformis," apparently (partim) our caudo- 

 femoralis, is represented to be superficial to the great sciatic nerve, 

 not deep to it as we have stated. That error is here a possibihty is 

 suggested by the following consideration. 



The femorococcygeus and the caudolemorahs muscles are very 

 closely apposed close to their insertions. It is here that the great 

 sciatic nerve passes through, sandAviched between them*; and by 

 its sheath it is so intimately bound up with the muscles that every 

 movement of the muscles must carry the nerve with them. This 

 may possibly be an arrangement for steadying the nerve during 

 rapid and extensive hip extension. In Lemur, and in Twpaia, such 

 a close association of the caudofemoralis with the femorococcygeus 

 around the great sciatic nerve does not occur. 



The tenuissimust is absent in Tarsius, as also in Lemur. 

 Klaatsch has shown it to be absent also in other species of Pro- 

 simiae. I find, with Leche, that it is present in Tupaia. 



The quadratus femoris is triangular in shape, as is characteristic 

 of Insectivora and Lemuroidea, and is inserted to the broad space 

 behind and between the lesser (2nd) and 3rd trochanters. It does 

 not occupy the extensive area of insertion found in Lemur, and 

 is thus more like Tupaia and Simiidae. The bulk of the various 

 muscles, in comparison wdth Tupaia and Lemur, forms an instruc- 

 tive study. . . 

 As a standard of comparison the weight of the rectus femoris is 



employed. 



All specimens were long preserved in spirit. 



Table I. 



* See Plate IV, fig. 1. , r, -, , ■. ,qqo 



t The iliofibularis (possibly) of Reptiha; Gadow, loc. at. 1«S-. 

 X \n arbitrary line of division had to be made m this specunen. 



