14 
Proceedings of the Royal Physical Society. 
Tergites 2-7 bear regularly 1 bristle below the stigma, with a few 
short bristles (3-5) before the row. The bristles of these rows are 
placed nearer to one another towards the median line than at 
the stigma, where they are somewhat wide apart. The supporting 
elements of the dorsal exoskeleton (teeth, spines, bristles, etc.) 
are generally odd in number, so that one falls in the median line. 
In connection with some of them are to be noted rib-like 
thickenings of the sclerite to which they belong; such thicken- 
ings added to the combs, and the more closely set spines, must 
Modified segments of Ischnopsyllus ashworthii, nov. sp. 
greatly increase the strength of this region of the skeleton. In barer 
species of the genus (eg. J. scitulus, Rothsch.) the same effect 
is produced by a general incrassation of the tergite, especially 
in the median line. 
APPENDAGES.— 
Manllary palpus.—The proportions of the joints are, 24, 14; 10; 18. 
Rostrum, 
“ i ‘ eR i Os il, 
1 Novitat. Zoolog., vol. xvi. (1909), pp. 58, 54, pl. viii. figs. 1 and 2. 
