282 Records of the Indian Museum. [Vor. XI, 
Lab e . . e 
The male specimen is at present on loan in America so I cannot 
give the description of it which ought to appear here. 
Group SELENOCOSMIEAE, 
This group, as defined above (p. 208), contains all the Indo- 
Australian Aviculariinae in which the anterior part of the labium 
is covered with densely packed granules, no matter whether a 
stridulating organ is present between the chelicerae and palps or 
not. 
The only known species which lacks the stridulating organ is 
‘© Tschnocolus’’ brevipes, Thorell, but in ‘‘Ischnocolus’’ subarma- 
tus, Thorell, this organ is quite rudimentary. The latter species 
was removed by Simon (Vol. II, p. 925) to the genus Phlogiellus, 
Poc., a genus which has since been shown by Hirst (1909, p. 384) 
to be indistinguishable from Selenocosmia and Chilobrachys. For 
the species subarmatus, however, he instituted a new subgenus 
Neochilobrachys, on account of the rudimentary nature of the 
stridulating organ (oc. cit., p. 389). 
Neochilobrachys subarmatus differs from species belonging to 
the genus Chilobrachys in having a much smaller number of 
stridulating rods on the coxa of the palp, and Chilobrachys differs 
from Selenocosmia in the same way. It was presumably for this 
reason that Hirst decided to regard Neochilobrachys as a subgenus 
of the former rather than of the latter. The change from the 
Selenocosmia to the Chilobrachys type of stridulating organ—of 
which many stages can be illustrated from species found at the 
present day—has, however, been accompanied by a marked in- 
crease in the specialization of the stridulating rods. The whole 
organ is clearly of a more advanced type in Chilobrachys than 
in Selenocosmia, and the reduction in the number of the rods 
cannot be regarded as in any way indicating a tendency towards 
degeneration—the only process which could bring them to the 
rudimentary condition of the ‘‘rods’’ found in Neochilobrachys 
subarmatus. The ‘‘rods’’? of N. subarmatus are, indeed, mere 
spines, comparable to those composing the dorsal and lateral parts 
of the groups of ‘‘rods” found in Selenocosmia, in which genus 
only the middle and ventral elements of these groups are really 
bacilliform. 
In my opinion, therefore, Neochilobrachys subarmatus should 
be regarded as a primitive form transitional between ‘‘ Jschnoco- 
lus’’ brevipes with no stridulating organ, and the genus Seleno- 
cosmia which possesses a stridulating organ of some complexity. 
In this case Neochilobyachys cannot remain as a subgenus of 
Chilobrachys; and as it differs from Selenocosmia more widely 
than does that genus from certain species of Chilobrachys, it may 
be regarded as a distinct genus. For the present it will be best, I 
think, to define this genus somewhat loosly, so that ‘‘ Ischnocolus”’ 
brevipes may be included in it. Otherwise yet another mono- 
specific genus would be required. 
