Nightjars and Kingfishers.

THE Caprimulgida, Nightjars, or Goatsuckers, as they are more generally called, are birds of nocturnal or crepuscular habits. They are appointed to thin the numbers of those million-breeding and destructive Phalana and coleopterous insects that come abroad only in the twilight of still evenings, and in this respect the Goatsuckers somewhat resemble the Owls. Their plumage and visual powers are accordingly adapted to this habit, and as their prey is caught upon the wing in a manner similar to that of the Swallows, but consists of larger and more powerful insects, the greatest facility in securing the prey is given by a striking modification of the

bill, or gape, and the production of a fence of stiff moveable bristles around its base. The fissure of the bill extends beyond the eye, and the base is extremely broad. The mouth is supplied with a glutinous secre

tion, which assists in quieting the prey when being conveyed to their young. The eyes and ears are large and prominent; and the wings, although, as well as the rest of the plumage, soft and of light texture, are powerful as instruments of flight, enabling the bird to turn and double in the air almost with the ease and rapidity of a Swallow. The feet are small and weak,

and the tarsi, which are generally covered with feathers, short. The toes are joined at their bases by a membrane; and the hind toe is partially united to the inner front toe, and in some species is directed forwards. The claw on the middle toe is broad, and often toothed or serrated on its inner edge.* The tail is generally long, even, rounded, or forked. Some of the exotic species are decorated with extraneous feathers, or other appendages, issuing from the wings, tail, or bill.

Most of these birds utter some peculiar cry, or whirring vibratory noise, which have obtained for them

* The use of this pectinated claw of the Goatsucker has not been satisfactorily ascertained. It has been supposed by some naturalists to give a firmer hold of the perch; by others that it is of use in capturing the prey; and by others, again, that it serves as a comb to rid the plumage on the head or vibrissæ of vermin or particles of dust, or other substances that might adhere to those parts. It is probable, however, that it is used in confining the struggles of its prey, where too large or strong to be swallowed at once, until the harder portions are removed or the insect is deprived of life. It may likewise be used as a comb, and modified so as to suit the laxity of plumage of these birds.