PACHYPTILA BANKSI.
which terminates the mandible ; the lateral portions of the bill are separated
from the culmen by a deep longitudinal grove on each side, expand considerably,
particularly towards the angles of the mouth, and internally the
cutting edge of each is armed with a row of very fine, closely set membranous
laminae, disposed in a transverse direction. Tarsi rather slender, and
coated with irregular flat scales ; feet rather large, the anterior margin of the
web belonging to the outer and middle toes semicircular, that of the middle
and inner ones very oblique, a form necessary on account of the inferior length of
the latter toe; anterior claws slender and moderately curved, the posterior one
straight, short, and pointed, and supplies the place of the hinder toe. Wings
long, and when folded reach nearly to the apex of the tail; the first quill feather
longest, the second slightly shorter, several of the others diminish in length
successively, but in a greater ratio. Tail rounded, the two centre feathers
being nearly an inch longer than the outermost one of each side.
DIMENSIONS.
Length from the point of the bill
Inches.
to
Lines.
Length of the tarsus.................
Inches. Lines
........ i *i the tip of the tail........... ... 10 0 of the outer toe............. ......... 1 3
of the bill from the angle of of the middle to e ....... ......... 1 3
the mouth........................ 1 4,1 of the inner toe............. ......... 1 1
of the wings when folded ... . . . 7 9 of the hinder toe ........ ....... 0 1 £
of the ta il...................... . 3 9
Judging from an imperfect specimen of a male bird of this species, which
I once saw I am inclined to believe the colours are the same in both
sexes.
This species is easily to be distinguished from P a c h y p tila v it ta ta Illiger, P ro c e lla r ia v itta ta
and carulect, Forst., P . F o r s te r i, Lath., by a variety of characters, but most readily by its b ill:
the latter in our species is much narrower, and the sides less oblique; the width at the base
is only seven lines, the width of P . F o r s te r i nine and a half; the sides of the bill in the latter
proceed more horizontally, and the bill itself is altogether much larger, and differently shaped;
the circumstance of many of the scapulars of P . v itta ta being broadly tipped with white, also
furnishes a good diagnostic character.
This bird appears to prefer the open sea to the vicinity of coasts, and though it occasionally
appears in the bays of the Cape peninsula during very stormy weather, yet it rarely continues in or
near them after the tempest which may have induced it to seek for the time a comparatively
placid retreat has subsided. I t is constantly to be seen from vessels sailing along
the eastern coast, particularly during the winter season; and it has often been a source
of amusement to me to watch how long and how perseveringly an individual of this species
would accompany a ship, even during blowing weather, without the appearance of having any
object in view, or of suffering any fatigue or inconvenience. It is rarely observed to settle on
the water, and if it does, it rarely continues passive longer than appears to be necessary to
enable it to seize and devour what may have induced it to rest.
The peculiar arrangement of the dull brownish-red colour, mentioned in the description of
the colours of the bird, gives to it when flying an appearance of having the wings and body
crossed by a dark coloured band.