1901.] ANATOMY or GRTJIFORM BIRDS. 645 



the apocentrie reduction oceu^^s also in two diastataxic forms — 

 Ar annus and Otis, 



Serratus superjicialis, Serratus profundus, Sterno-eoracoideus, 

 S'Ujpra-coracoideus, Coraco-brachialis extermis, Ooraco-brachialis 

 interims, BracliiaMs inferior, Suh-eoraco-scapularis, and Anconceus 

 are present in all : in most cases they do not present variations of 

 importance ; in some cases I have not materials to justify any 

 comment on the differences that I have noted. The portion of 

 the anconseus described by G-arrod and others as the Expansor 

 secundariorum presents in all what Garrod called the Ciconine 

 conditions : arising from a triangular ligament in the axilla, it is 

 inserted to several of the proximal secondary quills. It is feeblest 

 in Mhinocheius and in Eurypyga ; in the latter the tendon disappears 

 without actually reaching the secondaries, although at its origin 

 it has the strong Ciconine character found in the whole group, 



Ilio-tihialis internus seu sartoritis. — In all the Gruiformes this 

 muscle is practically identical. It arises (text-fig. 79, IL.-TIB.I.) 

 from one or two vertebrae at the proximal end of the ilium, and from 

 the ilium itself with a varying extent from the anterior vertical edge 

 and from the fasciae over the ilio-trochanterici ; in most instances 

 (not in the Gruinse) it is united with the proximal border of the ilio- 

 tibialis and it is inserted to the fasciae over the knee-capsule. 



Ilio-tihialis. — This large muscle arises by aponeuroses from the 

 dorso-lateral edge of the ilium in front and behind the acetabulum, 

 and is inserted along with the femoro-tibialis to the knee-capsule 

 (text-fig. 79, IL.-TIB.). An anterior, a median, and a post-ace- 

 tabular region may be distinguished in it. The post-acetabular 

 portion, the most variable in birds generally, is very large and strong 

 in all the Gruiformes. The median portion is reduced to a tendinous 

 sheet except in Eurypyga, where, after the origin, it is fleshy. The 

 anterior portion is tendinous in Balearica, but is fleshy after the 

 origin in the others. The extent of its fusion with the deeper 

 muscles of the thigh varies irregularly, but in many, as in PsopJiia 

 (text-tig. 79, IL.-TIB.), it is practically separate right down to the 

 knee. The special features of this muscle, the great development 

 of the post-acetabular portion, the reduction of the middle portion, 

 and the relative reduction of the anterior portion are common 

 properties of the group. 



Ilio-trochanterici j)osterior, anterior, et medius. — These three muscles 

 appear in their maximum and typical development in Psophia. 

 The dorsal or posterior muscle (glufaeussecundus) arises from nearly 

 all the pre-acetabular part of the ilium (text-fig. 79, IL.TB.P.). 

 It is much the largest of the three and runs straight to its insertion, 

 by a strong short tendon, on the trochanteric surface of the femur. 

 The most ventral or anterior muscle (glutseus tertius) is next in 

 size; it arises (text-tig. 79, IL.-TB.A.) from the anterior or ventral 

 edge of the pre-acetabular ilium, and its tendon of insertion is the 

 most distal of those on the trochanteric surface of the ilium. The 

 median muscle (glutaeus quartus) is much smaller ; it lies between 

 theothers (text-fig. 79, /Z.-ri?.iIf.) in its origin, course, andinsertiou, 



