ANATOMY OF THE SHOE-BILL. 673 



Flii-bi'inger is tlie most proxiraally placed, and is distinct altliough 

 very flat and weak throughout its whole length from its origin at 

 the proximal side of the brevis muscular peak to its insertion to 

 the recuri'ent beta slip. 



The course of evolution of the brevis tendon appears to have 

 been from a wide rather diffused band to first a specialization of 

 portions of that band into the slips distinguished by Fiirbringer, 

 then to a separation of these slips, and finally to the loss of one or 

 more of them. In the Storks, Herons and Scopus the slips are 

 at least separate distally ; in Storks and Herons the separation of 

 alpha and beta is only distal and does not begin so high up as in 

 Bcdcenicejys, in which, although the actual sepai-ation occurs only 

 about half-way down the patagium, the identity of beta can be 

 traced right up to its origin. Beddard figures an almost 

 similar, condition for Scopus (2, fig. 2). So also the very com- 

 plete separation of gamma and beta occurs in Scopus and 

 Balceniceps, and is much less distinct except distally in Storks and 

 Herons. The resemblance between Balcenicp/ps and Scopus appears 

 to be rather close; the most important differences being the 

 greater distinctness of the anchor to the longus in Scopus, and 

 the presence of an anchor to the humerus in the same bird. 



Deltoides major (text-fig. 125, Del. 1, Del. 2, Del. 3, p. 669; 

 text-fig. 126, Del.m.; text-fig. 128, De.). — This large muscle arises 

 fleshy from the scapula but with a distal tendinous anchor just 

 external to that of the anconajus, and is inserted flesh}'- to nearly 

 half-way down the humerus. It is very nearly divided into 

 the two portions visible in Leptoptihis and other storks. The 

 tendinous anchor occurs in the Herons and Storks that I have 

 dissected, and Beddard has recorded it in Scopus. 



Deltoides minor. — This muscle, possibly owing to the large size 

 of the deltoides major, is not to be distinguished as a separate 

 muscle : probably it is absent. In Storks it is small and quite 

 separate. 



Scajndo-humercdis antetHor. — This small muscle is absent. In 

 Steganopods, Storks and Herons it lies very close to the teres 

 major, so that it is possible that it may have fused with this in 

 Bcdceniceps. Beddard does not mention it in his description of 

 the shoulder muscles of Scopus, so that possibly it may also be 

 absent in that bircl. 



Sccqndo-humeridis posterior i^Teres major) (text-fig. 125, SP). — 

 A strong but relatively rather small muscle arising from about 

 the distal half of the scapula and inserted to the humerus between 

 the two heads of the anconeus. A relatively narrow insertion, 

 according to Fiirbringer, also occurs in Steganopods, Storks 

 and Herons. In Balceniceps it has no accessory anchors or 

 attachments. 



Suh-coraco-scapidaris. — The coracoid head (Coracobrachialis 

 brevis of Garrod) is single and much smaller than the scapular 

 heads. It arises only from the proximal half to third of the 

 inner face of the coracoid, as in Storks and Herons, and converges 



