VI CAPRIMULGI 415 
with Ofus (1.e. Asio) and Bubo ; the latter genus and Strix occur 
in the Lower Miocene of the same country, Stri# also in the Malta 
caverns and in the Mare aux Songes in Mauritius, Nyctea at 
Torquay and in France, Bubo in Wyoming, Badiostes in Patagonia. 
The Sub-Order CAPRIMULGI consists of the Nightjar or Goat- 
sucker group, with the Families Caprimulgidae, Podargidae, and 
Steatornithidae, of which the latter contains only the remarkable 
Guacharo. The Caprimulgidae may be divided into the Sub- 
familes (1) Caprimulginae and (2) Nyctibiinae. Authorities dis- 
agree as to the exact relationship of these birds to their allies, here 
classified as Coraciiformes ; but that all are allies is certain, while 
both in appearance and habits Nightjars are decidedly Owl-lke. 
Apart from the Steatornithidae, the skull is flattened, the eyes 
are large, the beak is short and extremely broad, being hooked 
and toothed in the Nyctibiinae and occasionally decurved in the 
Caprinulginae and Podargidae ; the gape is enormously wide, and 
is im many cases provided with stiff bristles, which in Aegotheles 
have long lateral filaments. An appearance of great size is given 
to the head by the loose plumage. The feet are fairly strong, with 
the digits somewhat united basally; the anteriorly scutellated 
metatarsi vary from comparatively long and bare in Wyctidromus 
and the Podargidae to very short and feathered in Nyctibius. The 
outer toe of the Caprimulginae has only four joints, and the mid- 
toe has a pectinated claw, while in the Podargidae and some Capri- 
mulginae the hallux is partially reversible. The pointed wing has 
ten primaries, sometimes much elongated (p. 418), and eleven or 
twelve secondaries; the tail may be square, rounded, graduated, or 
forked, and has ten rectrices, occasionally lengthened or even 
racquet-tipped (Joc. cit.). The furcula is U-shaped, the tongue 
short; the slit-like nostrils are basal and overhung by a membrane 
and feathers in Podargus and Batrachostomus, whereas they are 
open and near the tip of the bill in Aegotheles, but soft, tubular, 
and often elongated in the Caprimulginae. The syrinx is bronchial, 
sometimes tending to tracheo-bronchial; the aftershaft is rudi- 
mentary; the adults have down only on the unfeathered tracts, 
while the nestlings have a thick covering of it, which is generally 
buff or grey, but white in Podargus and Batrachostomus, 
The length varies from about twenty inches in Nyctibius and 
Podargus to seven or eight in Caprimulgus parvulus and Phalae- 
fo) 
