286 MR. J. O. WESTWOOD ON NYCTERIBIA, 
Mr. Curtis thus generically describes the abdomen: ‘‘ Conic-depressed, composed of 
6 ciliated joints in the male, the last joint hollow beneath, producing a style in the 
centre, and terminated by two incurved pilose lamin” ; thus omitting all notice of the 
structure of the female abdomen. And his figure of Nyct. Latreillii exhibits a dilated six- 
jointed abdomen, the last joint being the longest, and rounded at the extremity, and with 
an additional transverse series of bristles at the base, indicating another basal segment. 
He has not represented the organs which he describes as belonging to the male. 
I now proceed to notice more concisely the peculiarities of organization in the 
species which I have myself examined. 
Mr. Hope’s Bengal insects are somewhat smaller than Colonel Sykes’s; but the 
structure of all their parts (except the abdomen) is so similar that I should even be in- 
clined to regard the former as the males of the latter. The abdomen is elongate- 
ovate, and conically produced to the extremity, where it is shortly truncate. It is com- 
posed of five joints, the last of which is furnished beneath with two elongated and gra- 
dually attenuated styles, which, in the dried state of the insect, are incurved and laid 
flat upon the under side of the joint : they are very slightly pilose, and from their being 
laid close together it is impossible to obtain a knowledge of any other internal organ 
which they probably conceal. 
In my Chinese species the abdomen is nearly oval, with the terminal segment some- 
what narrowed. It is furnished above with six transverse series of bristles placed at 
equal distances, giving the appearance of seven segments; but on closely examining 
them, the abdomen certainly does not exhibit any corresponding articulations, in the 
ordinary acceptation of that word, the tegument being continuous. The terminal seg- 
ment is furnished at its extremity with a pair of elongated styles, applied close together, 
bent downwards, and slightly pilose; and beneath these, arising from the base of the 
joint beneath, is an exserted and elongated fleshy style, dilated at the tip. ‘This con- 
struction is very similar to that of Hermann’s supposed males and to Mr. Curtis’s de- 
scription of the male of Nyct. Latreillii, and is evidently characteristic of the male sex. 
The bristles which arm the extremity of the palpi are very long, and the anterior 
cove are much shorter than in the preceding species. 
In one of Mr. Stephens’s dried specimens of Nyct. Latreillii, the abdomen is more linear 
than in Mr. Curtis’s figure, but is divided into six segments of nearly equal size, except 
the last, which is more conical and truncate at the tip, and is furnished beneath with 
two lamine, placed rather apart so as to exhibit a small central style. They are, how- 
ever, closely applied to the under surface of the segment. This is evidently, therefore, 
a male: but the other specimen is very differently constructed ; the abdomen is elon- 
gate-ovate, its upper surface exhibiting a large and smooth oval patch, ciliated at the 
extremity, and extending over more than one third of the base of the abdomen : this is 
followed by a densely pilose region extending beyond half the length of this part of the 
body ; then follows another transverse region, denuded of hairs, but ciliated at its ex- 
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