ALBINO—ALLANTOIS 9 
distinguishable by its yellow or light-coloured legs, while the other, 
the D. brachywra of Temminck, its young being the D. nigripes of 
Audubon, has those limbs dark or black. Both of them seem to 
occur in summer in Bering Sea, while they occasionally appear 
along the shores of China and California ; but nothing can yet be said 
as to their precise range. It remains to mention the smaller species 
of the genus, one of which, D. cauta, described by Gould, is not 
much inferior in size to the preceding, and owing to its wary 
disposition, indicated by the trivial name it bears, is extremely rare 
in collections. These are all known to seafaring men as Molly- 
mawks—a corruption of MALLEMUCK—and chiefly frequent the — 
Southern Ocean, as does also the Sooty Albatros, which, from its 
wedge-shaped tail, has been placed in a genus of its own, and passes 
as Phebetria fuliginosa. 
ALBINO (coll. n. albinism). A case of HETEROCHROSIS, pro- 
duced by the partial or total absence of the normally-present black 
pigment in the feathers and other parts. In complete albinos the 
pupil and iris are red, owing to the blood-vessels shining through 
these otherwise strongly pigmented parts. A lesion of the pulp of 
a growing feather not unfrequently prevents the deposition of pig- 
ment therein, but the pulp recovers as a rule after one or more 
moults (see COLOUR). 
ALECTORIDES, an Order proposed by Temminck in 1820 
(Man. @ Orn. ed. 2, 1. p. xev.) to contain the genera Psophia (TRUMP- 
ETER), Dicholophus (SERIEMA), Glareola (PRATINCOLE), Palamedea, and 
Chawna (SCREAMER). Sundevall subsequently (K. Vet. Acad. Hand- 
lingar, 1836, p. 120) substituted Otis (BusTaRD) for Glareola, but 
wholly dropped the group in his Tentamen (1872-73) wherein these 
forms are differently disposed. The Order has, however, been ad- 
mitted by several other systematists, and among them by Mr. Sclater, 
who, in 1880, made it include six Families (see INTRODUCTION). 
ALECTOROMORPH i, according to Prof. Huxley’s arrange- 
ment (Proc. Zool. Soc. 1867, pp. 456, 459), the fifth group of 
ScHIZOGNATHA, corresponding practically with the GALLIN& of 
Linnzus ; and, omitting the genera Opisthocomus (HOACTZIN) and 
Menura (LYRE-BIRD), with the section Gallinacei of Iliger’s RASORES. 
ALK, the old and apparently the more correct form of AUK. 
ALLANTOIS (from adAGs, a sausage). A sack-like structure, 
which during the very early development of the embryo grows out 
from the posterior gut into the body cavity, and extends rapidly all 
round the embryo in the space enclosed by the false amnion, forming 
then with the latter a highly vascular inner lining of the eggshell. 
This bag receives urine, and takes on respiratory functions in 
embryonic Birds and Reptiles. Towards the end of incubation the 
