THE BIRDS OF AUSTRALIA. 
between them. At the same time, we must observe that there appeared much 
variation in the different specimens of each of these supposed species ; and we 
consequently cannot speak with the same certainty respecting the difference 
of species in this group, as in groups less subject to variation. We therefore 
state our doubts on these points, while we follow the general plan which we 
have prescribed for ourselves in all such doubtful cases, of keeping apparent 
species distinct, until proof is given of their being identical. Mr. Caley calls 
all these birds by the native name of Benit I He observes that they are night 
birds, and seem stupefied when found upon the wing by day.” 
Gould met with the birds when in Australia, but this did not help him 
much ; however, on his return, upon geographical grounds, he separated two new 
species : the first from Port Essington, on account of its smaller size and pale, 
delicate coloration, and the second from South-West Australia on account of its 
smaller size and similar coloration to the eastern bird. He was not satisfied, 
however, about the species and forms and wrote therefore in the Introduction 
to the Birds of Australia : “ With no one group of the Austrafian birds have 
I had so much difficulty in discriminating the species as the genus Podargus. 
It is almost impossible to determine with certainty the older species described 
by Latham ; could this have been done satisfactorily, even in a single instance, 
it would have greatly facilitated the investigation of the remainder. Messrs. 
Vigors and Horsfield regarded the specimens in the Linnsean Collection 
as referable to three species, and have described them under the names of 
Stanley anus, humeralis, and cuvieri ; Latham’s description of the species named 
by him megacephalus accords so weU with the P. stanleyanus that I suspect 
both these terms have been applied to one and the same species, an opinion 
strengthened by Latham’s remarks as to the great size of the head and 
mandibles of his bird, the total length of which he states to be thirty 
inches, which is evidently an error. After examining a large number of 
specimens, comprising individuals of all ages, I have come to the conclusion 
that the Australian members of this genus constitute six species ; four of 
which, namely, P. megacephalus, P. humeralis, P. cuvieri and P. hrachypterus, 
are most closely allied to each other ; and two, namely, P. plumiferus and 
P. phalcenoides, which present specific characters that cannot be mistaken . . . 
So great a similarity in plumage reigns throughout the first four of the 
species enumerated below that I have thought it unnecessary to figure more 
than two, viz. P. humeralis and P. cuvieri ; the other two may be readily 
distinguished by the descriptions I have given of them, particularly if 
the localities be attended to.” Under P. megacephalus Gould observed: “In 
the general colouring, form and arrangement of its markings, this species so 
closely resembles the P. humeralis that one description applies equally to 
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