448 SYSTEM A TIC SYNOPSIS — PICA BI^ — CYPSELIFORMES. 



rectrices. In certain genera, either wing or tail develops a pair of immensely lengthened 

 feathers. Feet extremely small; tarsus usually short, and partly feathered; hind toe very 

 short, commonly elevated and turned sideways; front toes connected at base by movable web- 

 bing, and frequently showing abnormal ratio or phalanges, the 4th toe having but 4 joints 

 (p. 127, fig. 41) ; middle toe lengthened beyond the short lateral ones, its claw usually pecti- 

 nate (fig. 291). The oil-gland is nude, and coeca are present. The arrangement of the leg- 

 muscles is anomalogonatous (p. 195); the ambiens and accessory femoro-caudal are both 

 absent. 



A definitely-circumscribed, easily-recognized group of about 14 genera and rather more 

 than 100 species, of temperate and tropical parts of both hemispheres. They are all more or less 

 nocturnal, and have a certain resemblance to owls, — particularly the genus Steatornis, which is 

 quite owlish. The flight is perfectly noiseless ; the plumage is very soft and lax, as in owls, 

 and the colors are usually blended in the most intricate pattern. The Caprimulgidce are 

 divisible, according to the structure of the feet, into two subfamilies : Podarginm, chiefly Old 

 World, with the normal ratio of phalanges, and CaprimulgineB (as below). Considering, how- 

 ever, other points, particularly the shape of the sternum, a more elaborate division is into (1) 

 Podargince, phalanges normal, tarsus naked and lengthened, sternum doubly-notched, with 

 three genera {Podargus, BatracJiostomus, and ^gotheles of the Old World ; (2) Nyctibiince, 

 phalanges normal, tai'sus short, feathered, stenium doubly-notched, upper mandible toothed, 

 containing one genus (Nyctihius) of tropical America ; (3) Steatornithincs, phalanges normal, 

 sternum singly-notched, with one remarkable genus (Steatornis) of tropical America, which 

 might properly be made type of a separate family, so many are the peculiarities of this owlish 

 bird ; and finally (4) Caprimulgince, comprising the rest of the family. The latter alone is 

 represented in North America. Our " Whippoorwills " are typically caprimulgine, and give a 

 good idea of the essential characters of the family; our "Night-hawks" are more aberrant, 

 representing a particular section of the subfamily ; but neither of these gives any hint of the 

 singular shapes which some of the genera assume. 



30. Subfamily CAPRiMULCIN>E : True Goatsuckers; Night-Jars. 



Sternum singly-notched on each side behind ; its body not 

 square. Ratio of phalanges abnormal. Outer toe 4^-jointed; 

 middle claw pectinate; hind toe very short, elevated, semi-lateral; 

 anterior toes movably webbed at' base (fig. 41); lateral toes not 

 nearly reaching base of middle claw. Tarsus very short, com- 

 monly much feathered (longer and naked in Nyctidromus and 

 Phalcenoptilus) . Besides the semipalmation of the feet, there 

 is another curious analogy to wading birds ; for the young are 

 downy at birth, as in Prcecoces, instead of naked, as is the rule 

 among Altrices. The plumage is soft, and lax, much as in the 

 Owls; the birds have the same noiseless flight, as well as, in 

 most cases, nocturnal or crepuscular habits ; and some of them 

 bear an odd resemblance to Owls. Besides this flufiiness and 

 laxity of the plumage, the skin is very thin and tender; it is 

 difficult to make good specimens of the whippoorwills, and the 

 curiously variegated blended shades, of exquisite beauty, like 



^,. ^^ , , , ^ the powdery coloration of a moth's wings, are at best not easy 

 Fig. 290. —Night-hawk, a glab- ^ ., . ., , . e .^ ■ ^-u ■ ^^ 



rirostral Caprimulgine. (From Ten- to describe. An evident design ot the capacious mouth is tlie 

 ney, after Wilson.) capture of insects; the active birds quarter the air with wide- 



open mouth, and their minute prey is readily taken in. But they also secure larger insects in 

 other ways; and to this end the rictus is frequently strongly bristled, as in the Tyrannidce. In 



