BROWN GANNET (BOOBY). 73 
the primaries, then the scapulars and feathers of head, and secondaries, with the 
tail-feathers, this first feathering being a brownish-grey. This colour is general 
on head, back and wings, with dirty-greyish breast, abdomen, and under-surface 
of wings when they fly. The young birds hatched out often show great disparity 
in size, one being hatched some days later than the other. This usually results 
in only one surviving, as, in proportion to the number of nests containing a pair 
of eggs, very few seem to rear more than a single young one. The naked skin on 
the face of the adult Brown Gannet shows a good deal of variation in colour, some 
being of a greenish-yellow, others of quite a blue colour. 
Nest.—A small hole scratched in sand, sometimes a few pieces of sponge, etc., 
strewn round. 
Eggs.—Clutch, two; bluish-white, covered with lime; axis 53-63 mm., 
diameter 3646. 
Breeding-season—July onwards to October (2). 
Distribution and forms.—Throughout the tropics, breeding on isolated islands ; 
forms insufficiently studied and the only fact certain is that two subspecies can be 
admitted : S. 1. leucogaster Boddaert, the Atlantic Ocean form, and S. J. plotus 
(Forster) from New Caledonia, for Australian birds which are larger than typical 
birds, and deeper brown coloration above. 
Genus PISCATRIX. 
Piscatrix Reichenbach, Nat. Syst. Vogel, p. v1., 1852 (71853). Type (by original designation) : 
Piscatrix candida Reich. = Pelecanus sula Linné. 
Large Suline birds, comparatively small for this family, with long straight 
bilis not hooked but bent at the tip, long thick neck, long wings, short legs and 
long toes, all the toes, including the hind-toe, being connected with a web. 
The bill is longer than the head, rather broad at the base, laterally compressed 
anteriorly ; culmen ridge flattened and separated from laterals by a linear groove 
extending the whole length of the bill and showing no nostrils. The edges of the 
mandibles coarsely serrated, the serrations obsolete towards the base, the rami of 
lower mandible strong and deep enclosing a very narrow unfeathered pouch, the 
featherless tract extending round the base of the mandibles and round the eyes, 
the chin being naked. The culmen is less than half the length of the tail and more 
than twice the length of the metatarsus. The wing is long, but not twice the length 
of the tail ; the first primary is longest. The tail is very long and wedge shaped ; 
it is composed of fourteen or sixteen feathers: probably the latter is the full number, 
the former due to age or moult. It is more than twice the length of the culmen and 
more than half the Jength of the wing. The legs are short and stout ; the metatarsus 
is coarsely reticulate throughout, the scales smaller on the back; in length the 
metatarsus is less than half the culmen. The toes are long, the outer one slightly 
exceeding the middle one, which has the claw pectinated ; the outer toe is about one 
and a half times the length of the metatarsus ; all the toes are fully webbed, the 
hind-toe connected to the inner with a web. The toes are reticulate ; this is peculiar, 
as generally in birds even having different metatarsal covering the toes bear regular 
scutes, apparently for ease in bending. This would seem to be the oldest toe-covering, 
but examination of the downy young of this genus shows the toe-covering to be more 
or less reticulate at that stage, the anterior joints showing irregular scutes broken 
up, the posterior joints regular reticulation. The downy young also shows no 
pectination on the middle claw ; in the bill in the same stage a rather distinct hooked 
tip is seen and the nostrils are distinctly shown as linear slits in a broad groove 
between the culmen and lateral edge, while serrations are not yet in evidence on 
the edges of the mandibles. 
