80 STRUOTUEE AND CLASSIFICATION OF BIRDS 



Alcedo hengalensis} It arises in other birds from the spinal 

 processes of a varying number of cervical and dorsal vertebrae. 

 The narrowest area of origin is seen in Alcedo, Macrochires, 

 and various passerines, where it embraces at most a single 

 vertebra. In other birds it may arise from as many as four 

 and a half vertebrae. The broad fleshy or tendinous, or 

 partly, fleshy and partly tendinous, insertion varies in width. 



The second division is entirely wanting in Otis, Pterocles, 

 many passerines, &c. It arises from the spinous processes of 

 posterior dorsal vertebrae, ilium, and even adjacent ribs. Its 

 origin is usually widely separated from that of anterior ; but 

 there are various intermediate conditions which culminate in 

 the cuckoos, Macrochires, and some other birds, vvhere the 

 two muscles form one, with, however (save in Cypselus), 

 separate insertions. The insertion of this muscle is by a ^ 

 slender tendon in front of that of the latissimus dorsi 

 anterior. 



The latissimi dorsi metapatagialis and dorso-cutaneusa 

 are two slips running to the metapatagium and the neck 

 region of the skin respectively. They are not often both 

 present, but are in Apteryx, Charadridae, Alcidae, and some 

 gallinaceous birds. They are both absent in ratites (excl. 

 Apteryx), Macrochires, Colii, Bucerotidse, &c. The dorso- 

 cutaneus is the rarest, and apart from the instances mentioned 

 is found only in the Cracidae, piciform birds, and passerines. 



Cucullaris. — This is an extensive muscle occupying the 

 greater part of the neck. The only muscle superficial to it 

 is the sphinctor colli. It has two main divisions. The 

 pars cranialis arises from the region of the occipital and the 

 squamosal ; in many birds (of the most diverse orders) a 

 branch is given off from this (the dorso-cutaneus) , which 

 ends on the back below the spinal pterylon, whose feathers 

 it raises. The main part of the muscle ends upon the 

 clavicle, or sternum, or ligaments in the neighbourhood. 

 In some birds a part of the fi*bres end upon the fascia 

 covering the pectoralis primus, and in those with a crop 

 some of the deeper fibres come into relation with that 

 ' Not in A. 



