CAPRIMULGIN.E. 87 



long, lumbar tracts. The axillary tracts also appeared to me to be somewhat longer than in 

 llemiprocne. This species possesses eighteen remiges. In its contour-feathers I was struck by 

 the circumstance that all the barbs of the main shaft, even to the very lowest, possess a 

 pennaceous structure at the base, and only become downy towards the end. This remains the 

 same up to two thirds of the entire feather, but the downy part gradually increases in 

 length. The oil-gland is here proportionately still smaller than in Trochilus, and is also much 

 narrower and more acute. 



2. Trochilus (Plate III, figs. 18 and 19). The group-character of the Humming Birds, as 

 regards their pterylosis, is therefore the smaller aftershaft on the contour-feathers, which 

 I have recognised distinctly only on the large feathers of the rump, and also the absence of down- 

 feathers on the spaces ; further, the broad rhombic form of the spinal tract, the very long and 

 rather broad spinal space, extending from the scapulae to the oil-gland, and the slight, scarcely 

 perceptible development of the lumbar tracts. Whether the nape-space (see PI. Ill, fig. 19) beneath 

 which the long cornua of the hyoid bone are situated, found by me in T. moscliitus, occurs in all 

 the species, I cannot decide, from a deficiency of investigations. In several specimens preserved in 

 spirits, which I could not determine with precision, it was still larger than in the above-mentioned 

 species. Moreover, the cordate oil-gland, furnished with a short tip, is remarkably broad and 

 large for so small a bird. 



2. CAPRIMULGIN^E. 



(Cuculinae nocturnes NITZSCH.) 



This family very closely approaches Cypsclus pterylographically, but the contour-feathers have 

 a weaker aftershaft, and the wings contain from twenty-one to twenty-two remiges, ten of which 

 are seated on the hand. The oil-gland is remarkably small, probably the smallest in proportion that 

 occurs in the whole class of birds ; it is of an elongated oval form, without a circlet of feathers at the 

 tip. The forms of the tracts, singularly enough, have a remarkable resemblance to the type of several 

 Rapacious Birds, but differs in the various genera. Among these analogies I reckon the forking 

 and interruption of the spinal tract between the shoulder-blades in Caprimulgus, the emission of 

 an interior branch from the end of the gular portion of the -inferior tract in Nyctornis, and the 

 division of the dorsal and rump portions of the spinal tract in the same genus. We may, therefore, 

 regard as the chief peculiarity of the family the densely feathered vertical band, which is readily 

 distinguished from the sparse plumage of the head, and passes behind into the cervical portion of 

 the spinal tract ; this has not occurred to me elsewhere, and it is the more remarkable in this 

 group, as none of its members possess a large and striking feather-crest. 



1. Caprimulyus (Plate IV, figs. 1 and 2). Two rows of sparse contour-feathers run on each 

 side of the densely feathered vertical band (at least in C. europaus). Spinal tract at first broad, 

 forked between the shoulder-blades, each branch united to the broad rump-band by a single row 

 of contour-feathers. Lumbar and humeral tracts very broad. Inferior tract divided from the 



/ 



commencement of the throat, without an interior branch at the base of the neck, but with a 



