1885.] 



MYOLOGY OF THE WATER-OVOSSUM. 



Fig. 3. 



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 ■ E.S.I P. 



-^E.O.M.P. 



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Myology of Water-Opossum, 



.(1. JE., anconeus externus ; ^. &'././'., extensor secundi iulei-notlii pollicis; E.O.M.P., 

 extensor oasis metacarpi pollieis ; .S'.B., supinator brevis; .'/./..anconeus 

 internu.s ; F.C.U.. flexor carpi ulnaris ; li.A., brai-hialis anticus ; BL, 

 biceps ; S.li., supinator brevis ; F.D.I'., flexor digitorum profundua ; 

 P.li.T., pronator radii teres; P.Q., pronator quadra tus. 



Muscles of Posterior Extremity. 



Gluteus maximus. — A thin triangular muscle, arising chiefly by 

 fascia from anterior superior spine of ilium, from transverse pro- 

 cesses of sacral vertebrae, and from caudal vertebrae as far as third 

 or fourth. Anterior and middle fibres converge to be inserted into 

 outer as|)ect of root of great trochanter ; posterior fibres inserted into 

 linea aspera for its upper two thirds. It is quite free posteriorly, 

 but in front turns round gluteus medius and joins anterior border of 

 gluteus minimus. 



Gluteus medius. — Thin posteriorly, but thick and partly divisible 

 into three laminae anteriorly. Arises from dorsum ilii, anterior 

 superior iliac spine, and sacral vertebrae, continuous anteriorly with 

 gluteus maximus. Its superficial part is inserted into outer surface, 

 its deep part into upper border of great trochanter. 



Gluteus minimus. — Thin, arising from border of ilium between 

 iliacus and gluteus medius. Inserted into anterior border of great 

 trochanter, being continuous both at its origin and insertion with 

 gluteus maximus. 



Gluteus quartus Thin muscular fibres, closely applied to capsule 



of hip-joint, arising superficial to rectus tendon and closely connected 

 with it. It is inserted just below inner part of neck of femur 

 between psoas and vastus internus. 



Pyriformis. — Arises from side of sacrum half an inch behind sacro- 



