Australian Birds in the Collection of the Linnean Society. 195 



Vibrissa mastacales ad apicem simplices, ad basin pecti- 

 nate ; capistrales numerosoe, longissimœ, porrectas, utrin- 

 que pectinate. Nares in medio rostri positee, lineares, 

 obliqvia% subpatulœ, posticè angustiores. 



ALe breves, rotiuidata;. Kemiges prima et sexta ferè eequales 

 brevissimaj, -ecunda et quinta œquales longiores, tertia et 

 quarta axjual, s longissima3 ; secundœ pogonio externo levi- 

 ter, tertiee ad quintam inclusara pogoniis externis profundè 

 emarginatis : secundiie ad quintam inclusam pogoniis inter- 

 nis emarginatis. 



Pedes congrui. Tarsi elongati, subgraciles, compressi, nudi. 

 Digiti iiberi, subgraciles, ferè lequales. Hallux longus, 

 debilis. t//?o-«es compressissimi, medio integro. Acrotarsia 

 acropodiaque scutulata ; horum scutis confertis approxi- 

 mantibus. 



Cauda mediocris, rotundata. 



The perfection of the family of Caprimulgidce may be con- 

 sidered as most fully exhibited in the true Caprimulgus, Auct., 

 of which the conunon European species is an adequate example. 

 In that genus, which forms part of the typical group of the 

 Fissirostral tribe of the Insessores, the chief characters that dis- 

 tinguish the birds of the tribe are strongly developed, namely, 

 the powers of tlight and of receiving their food within the wide 

 gape of their bill when on the wing. The chief strength of the 

 bird is thus centred in the winos and the rictus of the bill ; and 

 a proportional deficiency takes place in those other members 

 which are less necessary to it in the performance of its peculiar 

 functions. The bill itself is feeble, and apparently useless in 

 securing its prey, which object is effected chiefly by a viscous 

 exudation within the gape, and a regularly disposed network of 

 strong bristles, which externally margins the rictus. The legs 



2 c 2 also 



