1905.] 



ANATOMY OF LIMICOLIXE BIRDS. 



159 



Its insertion is musculai-, and just below tliat of the posteiior 

 division (text-fig. 26, L. A. and 3). The posterior division is absent 

 in Scolopax, present in the otheis, and its proximal edge touches 

 the distal edge of the anterior division in GJdicnemus (text-fig. 26, 

 L.P. and 4) and Hydrophasicmus, but not in the others. In Hydro- 

 phasiani(,s and (Edicnemus the two muscles are almost continuous, 

 although they cross before insertion, at which point they are closely in 

 contact ; whilst in the others the tendon of the posterior division is 

 sepai-ated by a short gap from the muscular and more distal insertion 

 to the humerus of the anterior division ; this tendon is always 

 in close association with the humeral anchor of the anconseus. 



Text-fio-. 26. 



Slioulder-muscles of (Edicnemus scolopax. 

 Left shoulder ; external view. 



Tendon of supra-coracoideus. A.S. Ancouaeiis scapularis, the reference lines 

 pointing respectively to the humeral origin and the scapular anchor. S.A. 

 Scapuli-humeralis anterior. S.P. Scapuli-humeralis posterior. S. Expansor 

 secundariorum. L.A. Latissimus dorsi anterior. L.P. Latissimus dorsi 

 posterior. 3. Insertion of lat. dors. ant. 4. Common insertion of lat. dors, 

 post, and humeral anchor of ancon. scapularis. 



The posterior division, where present, tends to spread backwards 

 to reach the ilium and part of the ribs. In Chionis its origin is 

 limited to the vertical anterior edge of the ilium, whilst the gap 

 between it and the anterior muscle is wider than in any of the 

 other birds. 



The archecentric, or most generalised, condition of these muscles 

 in Birds appears to be the existence of an anterior and posterior 

 division, fairly well separated at their origins and close together 



