104 THE VOYAGE OF H.M.S. CHALLENGER. 



Gluteiis medius (V), Reid, p. 143. 

 Gluteus mmimus, Owen, p. 34. 



GhdeiLs minimus et quartus, Selenka, vol. vi. p. 140, No. 77. 

 Petit fessier, Gervais and Alix, p. 31. 



Attachments. — The gluteus minimus arises from the posterior two-thirds of the 

 external border of the iliac bone in front of the acetabulum, as well as from an ajioneurotic 

 septum which separates the gluteus medius from the gluteus minimus. The fibres pass 

 obliquely backwards and outwards, and are inserted by means of a narrow tendon into a 

 depression on the outer surface of the great trochanter of the femur, at the junction of 

 the latter with the shaft of the bone. 



Action. — It flexes the hip joint powerfully, and co-operates with the gluteus medius 

 in rotating the foot outwards. 



Relations. — This muscle is in great part concealed by the gluteus medius. Its lower 

 border, however, projects beyond that of the muscle just named. The tendon of insertion 

 is attached below that of the gluteus medius, being separated from the latter by the 

 tendon of insertion of the obturator externus. 



Nerve siqjj^Ij/. — A branch from the anterior crural. 



Variations. — In Eudyptes chrysocome from the Falklands, in Eudyptes clirysolophus, 

 and in Pygosceles tceniatus the origin of the muscle is less extensive than above de- 

 scribed, being confined to the posterior half of the iliac bone. In Eudyptes clirysolophus, 

 moreover, the muscle cannot be separated without artificial dissection from the gluteus 

 medius. 



In Aptenodytes I observed a tendency on the part of this muscle to divide into two 

 distinct portions, an upper and a lower, a cellular interval lying between them. 



Remarks. — In a number of birds, e.g., the common fowl, in addition to the gluteal 

 muscles above described, there is one (the gluteus medius of Tiedemann, the ibaque 

 ant^rieur of Vicq d'Azyr) which arises from the lower half of the anterior margin of 

 the iliac bone, and is inserted into the great trochanter of the femur. Of this muscle the 

 Penguins do not possess the slightest trace. 



According to Gervais and Alix, the smallest gluteal muscle in Eudyptes chrysoloplms 

 is inserted into the inner surface of the femur. Neither in the species named, nor in any 

 other species of Penguin, did I find this statement to be correct. On the contrary, in all 

 the gluteus minimus is inserted, as above described, into the outer surface of the femur. 



3. Cruro-coccygeus. 



Cruro-coxcygien, Vicq d'Azj'r, 1774, p. 496, No. 3. 

 Schenhel-Stdssbein-Miishel, Wiedemann, p. 98. 

 Erster Seitenvmskel des Schicanzes, Tiedemann, p. 294, No. 3. 

 Sclacanzliuftmuskel , Merrem. 



