Mr Appleton, The Gluteal Region of Tarsius spectrum 473 



ischiofemoralis* ; Carlssont identifies the corresponding muscle of 

 Hypsiprymnodon as the caudofemoralis. 



GregoryJ has fallen into the error of comparing the caudi- 

 femoralis of Reighard and Jennings (the Cat), in Parsons' meaning, 

 with the caudofemoralis of Hypsipnjmnodon in Leche's sense of 

 the term. 



In the present state of the literature, it is indeed not possible 

 to compare muscles of similar name described by different authors 

 without further enquiry into the attachments and nerve-relation- 

 ships of these muscles. The position of the great sciatic nerve is 

 a ready method of distinguishing the femorococcygeus (caudo- 

 femoralis of Parsons) from the caudofemoralis (ischiofemorahs of 

 Parsons). 



The nomenclature of Leche has some claim irom usage, and is 

 here employed. Ischiofemorahs is an excellent descriptive narne in 

 certain more speciahsed mammals: but in the more primitive 

 animals (some Reptiha and Insectivora)§ a caudal\\ attachment 

 rather than ischial is found. If it is agreed to use different nanies 

 for what is practically the same muscle, according to interspecial 

 variations in its attachments, then there must be no verbal 

 homologisation of muscles. The caudofemorahs (or caudifemorahs) 

 muscles of certain authors are no more comparable with the 

 caudofemorahs of Leche and Carlsson than are the various muscles 

 which go by the name of pectineus in various mammalia homolo- 

 gous with one another. 



Some correlated changes in bones, associated with muscular 

 pecuharities of Tarsius, may be mentioned: 



(1) Large transverse processes to the first three caudal verte- 

 brae]}, associated with well developed femorococcygeus. 



(2) 3rd trochanter and descending extensor ridge on femur 

 [v. supra). 



(3) Marking on the posterior aspect of the femoral shaft for 

 attachment of caudofemorahs (paralled in Marsupialia). 



(4) Femoral shaft with high pilastric index— associated with 

 the powerful quadriceps extensor. 



The peculiar features of Tarsius deserve comparison with those 

 of other jumping animals. Some have been already considered. 



(1) Length of femur. In large jumpers (Macropodidae) shorten- 

 ing occurs for a similar reason in cursorial types**; viz. diminu- 

 tion of the necessary mass of knee-extensors. In small jumpers 



* Cunningham, loc. cit. 1882, also uses this term. 

 t Carlsson, A., Kungl. Svensk. Vetensk. Handl. 1915. 

 X Gregory, Bull. Amer. Mus. Nat. Hist. 1918. 



§ Also Hypsiprymnodon (Carlsson) and Monotremata (Westling, Bihang t. K. tbv. 

 Vet.-Akad. Handl. 1889). 



I| For M. caudofemoralis (Leche). 



'^ Cf. Duckworth, Morph. and Anthrop. vol. i, 1915, p. 106. 

 Appleton, loc. cit. 1921 



** 



