( 395 ) 



The pelvis of xipteri/x also shows variatious in the degree iu which the ilia meet 

 above the vertebral column. Dr. Mivart remarks that " the ilia do not quite 

 meet together dorsad behind the acetabula, though they are not so open as in 

 VromaeKs and Casuarius.^' I should have regarded it as the rule for this open tract 

 tlirough which the spines of the lumbar vertebrae are vi.siblo to commence rather ia 

 I'niiit of, or at least on a level with, the anterior margin of the acetabulum. 



3. MUSCULAR ANATOMY. 



The general muscular anatomy of Apteryx has been described by Owen ; 

 Garrod dealt subsequently with certain muscles of the thigh, and with the deep 

 ilexor tendons ; Furbringer has carefully gone into the shoulder muscles in his 

 great work upon birds ; T. J. Parker redescribed the muscles of the wing, correcting 

 Owen in several particulars ; finally Gadow's book upon birds contains the bulk of 

 what is known concerning the musculature of Apteryx. 



Muscles of the Hind Limb. 



Glutaeus primus. — This wide sheet of muscle is correctly described by all 

 authors as arising from the entire length of the ilium, post-acetabnlar as well as 

 pre-acetabular. I observed no variations worthy of remark. 



Glutaeus secundus. — This is, as usual, the most powerful of the three glntaei 

 which spring from the pre-acetabular ilium. It arises from the whole of the crest 

 of that bone in front of the acetabulum, and also from such parts of the surface of 

 the ilium as are not occupied by the two muscles ne.\t to be described. Some of its 

 fibres even spring from the septum between itself and those muscles. The insertion 

 is by a broad strap-shaped tendon. 



The Glutaeus tertius and Gl. quartus really form one muscle, with but indica- 

 tions of division. They are both covered by the last muscle, excepting the anterior 

 part of Glutaeus tertius. In A. kaasti they spring from the ilium and lie side by 

 side, the anterior of the two being slightly the smaller ; in .1. australis I was 

 unable to distinguish the two muscles, e.xcept just before their tendons of insertion. 

 In this species the tendons are inserted separately but contiguously ; in ^4. haaati 

 they are absolutely fused just before insertion. 



Glutaeus quintus. — This muscle is continuous at its origin with the Glntaeus 

 secundus ; it ends in a long strong tendon inserted between the tendons of the 

 femoro-caudal and Glutaei tertius et quartus. 



Obturator externus. — This muscle (called by Owen " pyramidalis ") arises from 

 the ischium, and is inserted fleshily beneath the tendon of the obturator internus by 

 a wide insertion considerably wider than that of tlie femoro-caudal. 



Obturator internus ends in a long round tendon which is as usual accompanied 

 by Gemelli. It overlaps the insertion of the last muscle. 



The Iliacus is a small mnscle with fleshy origin and insertion. 



The Femoro-caudal immediately underlies the accessory femoro-caudal. It is 

 distinguished by Garrod into two parts, one of which, arising from tlie candal 

 vertebrae, he separates as true femoro-caudal. I imagine that the pyramidal muscle 

 does represent both femoro-caudal and its accessor}-, but I can see no marked line 

 of division between them. The muscle arises chiefly from the ischium, but its area 

 of origin also strays on to the ilium and the caudal vertebrae. It is inserted 



