1 
THE BIRDS OF AUSTRALIA. 
characterised thus : “ Shafts of rectrices very stiff, with perceptibly prominent 
spinous points.” He stated : “ I cannot recognise the genus Hemiprocne, 
because the form of the tail alone cannot be regarded as being sufficient to 
separate genera in the Cypselidce, as the species of the genus Micropus clearly 
show.” 
By one of those peculiar coincidences that occur in scientific work, this 
assembly remained unquestioned until quite recently, though it was obviously 
based upon a very superficial feature, and one apparently of little value. 
The discovery of the use of Hemiprocne earlier than 1840 incited American 
ornithologists, and Oberholser recorded (Proc. Biol. Soc., Wash., p. 68, May, 
1906) : “ Doctor Hartert in his most recent review of the Swifts, placed 
Hemiprocne as a synonym under Chcetura, claiming that the shape of the 
tail was not sufficient for its recognition as a different genus. However valid 
such a claim may be — and it seems not to be so in this case — there can now 
be no doubt of the propriety of generically segregating the group of Swifts 
of which Hirundo zonaris Shaw may be considered the representative, 
because aside from its emarginate instead of square or rounded tail, it differs 
remarkably from Ghcetura in the arrangement of the deep plantar tendons.” 
Nevertheless it escaped the notice of British ornithologists that super- 
ficially the large Needle-tailed Swift, tliat has occurred twice in their hmits 
and hence is considered a “ British Bird,” was separable frorp the small 
American species, and they continued the misusage of Ghcetura. 
There are two very distinct groups, differentiated by size: large birds, 
including the Australian caudacuta ; and small ones, which are not represented 
in Austraha in any group. It is necessary to discuss the whole series classed 
by Hartert under Ghcetura to define the name to be used for the large Austrahan 
bird. Since I drew up my notes, I find that Ridgway in the Bulletin U.8. 
Nat. Mus., No. 50, covering pt. v. of the Birds of North and Middle America 
has given a Key to these birds, but as usual with Keys it is deficient in 
some way. Deahng with American birds especialty, extra-limi tal genera are 
sometimes diagnosed, but not so much study being given to the latter the 
details are not perfect. Thus criticism of these extra-limital groupings is 
inevitable, and it does not detract from Ridgway’s great work if these be not 
found faultless. Thus, he admitted a subfamily Ghceturince and one of the 
items of his diagnosis reads : “ Tarsi and toes naked ” : just previously he 
had referred to the oriental genus Gollocalia as belonging to the subfamily 
Ghceturince. The “ genus ” Gollocalia as accepted by Ridgway, however, 
included species with “ feathered ” tarsi, an item overlooked on account of 
the non-inclusion of the said genus in the North American fauna. 
Ridgway admitted four genera where Hartert accepted one only : thus 
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