342 STRUCTURE AND CLASSIFICATION OF BIRDS 



views respecting the families into which the Limicolae have 

 been divided. 



An expansor secundariorum is almost universally present, 

 but is often feebly developed. It appears to be absent in 

 Tringa canutus and Chionis. 



The biceps is so far noteworthy that only the coracoidal 

 head is present in Rliynclicea and in Parra sinensis. 1 The 

 condition of this muscle in Himantopus is extremely 

 interesting. It is stated by Dr. GADOW (on the authority of 

 MECKEL) to be a double muscle. In H. nigricollis I find 

 the following arrangement : There are two distinct portions 

 (1) a part which may perhaps correspond to the entire biceps 

 of other birds, with two heads, a coracoidal and a humeral ; 

 from the former of these arises the biceps slip : (2) in addi- 

 tion there is a distinct coracoidal portion, with a fleshy 

 belly, which has, however, a common origin from the coracoid 

 with the coracoidal head of the main muscle. Something of 

 the same kind appears to occur in Chionis and Scolopax ; it 

 may obviously be compared with the gulls (q.v.) In Cur- 

 sorius the biceps was also double, though the division only 

 commenced a little below the level of the humeral attachment. 



In Lobivanellus there were indications merely of the same 

 division in the lower part of the belly of the muscle. Glareola 

 has a biceps which is double for the greater part of its course. 



The anconceus appears to invariably possess the tendinous 

 humeral head. 



My remaining notes upon the myology of the group are 

 scanty. In Lobivanellus atronuclialis, the semimembranosus 

 and semitendinosus are inserted by a common tendon, and 

 the latter gives off a branch to gastrocnemius. There is but 

 one peroneal muscle (the longus). The latter is alone 

 present in Chionis alba and Himantopus niijricollis. The 

 pectoralis primus in these birds does not appear to be 

 divided into two layers. 



There is some variation in the deep flexor tendons of this 

 group. 



1 In this bird the biceps slip arises (as figured by FURBKINGEK) from the 

 humerus itself. 



