Genus NYCTIDROMUS, Gould.

CHARACTERES GENERICI.

Rostrum mediocre, ad basin latissimum, hiatu amplissimo, rictu setis elongatis mstructo. Nares sub-basales, elevate,
transversim subovales, aperte. Ale mediocres, remige tertio ceteris prestante, Cauda elongata, ampla, subrotundata.
Tarsi nudi, elongati, antice scutellati. Digitorum externus et internus breves, intermedius elongatus, ungue pectinato ;
digitus posticus liber, parvus, et ungue parvulo instructus.

NYCTIDROMUS DERBYANUS, Goud.

Nyct. fronte, vertice, nuchd, et regione interscapulart cinerescentibus, minutissime mgro punctatis ; vertice et nuchd lined
wregulart nigra ornatis ; genis, plumis auricularibus, mentoque rufo-fuscis, hic obscure mgro fasciato, lined cervind ab
angulo oris ; ale tectricibus rufo, cervino, nigroque ornatis ; primariis ad basin mgrescentibus, rufo fasciatis, in medio
albis, ad apicem nigrescenti-fuscis ; secondariis rufo fuscoque fasciatis ; scapularibus rufis, nigrescenti punctatis et
lineatis necnon cervino-marginatis ; dorso imo, rectricibusque caude duabus intermediis sordidé cervuus, nigro pun-
ctatis, et obscure fasciatis; rectrice externd utrinque nigra, intis albo marginatd ; reliquis albis; corpore subtus cervino,
Susco fasciato ; pectore superiore plagd albd semidivisd ornato ; rostro pedibusque brunneis.

Long. tot. 12 une.; rostri, 12; ale, 7; caude, 7; tarsi, 14.

: Forehead, top of the head, back of the neck, and space between the shoulders pale grey, minutely pencilled with
5) black, and with an irregular mark of black from the top of the head along the back of the neck; sides of the

IR

face, ear-coverts, and chin rufous brown, the latter obscurely barred with black, a stripe of buff running from
the angle of the mouth; wing-coverts mottled rufous, buff and black, each feather largely tipped with buff ;

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base of the primaries black, banded with rufous, to which succeeds a central band of white, the remainder being
‘ brownish black; secondaries alternately with brown and rufous; scapularies rufous brown, freckled with
y black, bounded externally with blackish brown, and margined with buff; lower part of the back and central
tail-feathers dirty buff, obscurely freckled and barred with blackish brown; outer tail-feather on each side
black, with a white internal margin ; the remaining tail-feathers white, under surface buff, barred with brown 5
a white semidivided gorget across the chest; bill and feet brown.

Nyctidromus Derbyanus, Gould, in Proc. of Zool. Soc. Part VI. 1838.

 

Tur members of this group are confined to South America; they run much on the ground, and are remark-
able for the great dilatation of the base of the under maxillary bones. There are at least ten species of this
peculiar form, among which has hitherto reigned the greatest confusion. The present bird, which I have
reason to believe has been confounded with other proximate species, I venture to distinguish by the title of
Derbyanus.

The figure is of the natural size, and is taken from a fine example kindly lent to me by the Earl of Derby.