208 CHJETURA PELASG1A. 



ORDER IV. CYPSELI. SWIFTS. 



Sternum, with no marginal indentations. Keel, very high. Bill, short, with a wide and 

 deep gape, but there are no bristles at the base. The plumage is not soft. 



The wings are exceedingly long and pointed, while the feet are moderately large and 

 provided with long, sharp claws admirably adapted to the purpose for which they are in- 

 tended; that of clinging to perpendicular walls. The eyes are quite large and many of the 

 species are semi-nocturnal in habit. 



FAMILY I. CILETUKID^E. THE AMERICAN SWIFTS. 



Joints of toes, normal in number. Coracoids, exceedingly short and set at a rather wide 

 angle. Furcula, short and arched. 



The body is extremely short and compact, consequently the legs and wings have their 

 origin quite near together, the knees when bent, coming on a level with the heart. The 

 tibae are long but the tarsi are short. The short furcula is well arched and is provided 

 with a very small terminal expansion. The humerus is very short, not more than one 

 half the length of the fore-arm which is normal in length, while the carpus and metacar- 

 pus are considerably elongated; the result of this modification is a very long, saber-shaped 

 wing. The skull is not large but the neck is quite long. The high keel supports very 

 large and firm pectoral muscles, thus the birds are exceedingly strong on the wing, having 

 apparently untiring powers of flight. 



GENUS I. CILETURA. THE CHIMNEY SWIFTS. 



GEN. Cn. Tail, short, with Ike shafts stiffened and extending beyond the webs in thorn-like spines. The mouth is provid- 

 ed with two peculiar (/lands, situated beneath the tongue. 



Members of this genus are noticeably characterised by the termination of the tail. The tarsi are naked and the tibse 

 are only partly feathered. The peculiar glands beneath the tongue are somewhat triangular in form and, during the nesting 

 season, secrete a viscid saliva which Ls exuded though a number of ducts that open along the inner edges, consequently, 

 directly under the tongue. The larynx is provided with a strong sterno-trachealis and also with a slight broncho-trachealis. 

 The tympaniform membrane is present and although there is an as transversale, yet it does not support a semilunar mem- 

 brane. The oesophagus is without dilatation. The proventriculus is small, with simple oval glands which are arranged in 

 a zonular band. The stomach is flat, rather round, the walls are thin and lined with a smooth membrane. The hoop of 

 the duodenum is short, encircling a rather long pancreas which extends along the intestine. The spleen is an oblong body, 

 situated directly over the cardiac opening of the stomach. The coeca are quite large. 



CH-SJTURA PELASGIA. 



Chimney Swift. 

 Chtftura pelasgia STEPH., Shaw's Gen. Zool. Birds, XIII; 1825, 76. 



DESCRIPTION. 



SP. CH. Form, rather slender. Size, medium. Sternum, stout. Tongue, short, thin, flatand horny, especially at the 

 tip but is not bifid nor provided with terminal cilia. When viewed laterally, this organ has a somewhat peculiar appear- 

 ance, as the first bone, the glosso-hyal, is placed higher than the remaining portions, the uro-hyal being bent downward; 

 thus the tracheal opening which approximates quite closely to the tongue, is considerably beneath its level. 



COLOR. Adult. Dark sooty-brown, throughout, darkest on the head, back, and wings wjiere there is a greenish gloss. 

 The wings and tail arc not dark and the throat is quite pale but gradually becomes darker on the breast. 



Young. This stage of plumage is scarcely different from the above, the general colors are, perhaps, darker, and the 

 primaries and scapularies are slightly edged with whitish. 





