364 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. VIII. 
genera from Pompilus, have not only in the genus Pompilus, as I 
hold it, but throughout the Pompilide generally, proved, at the best, 
mutable. Under these mutable characters may be reckoned the form 
of the prothorax and middle segment, of the relative positions of the 
transverse medial nervure, and the 1st submedial cell in the fore wing, 
and of the cubital nervure and anal cell in the hind wing, and the 
general armature of the legs and claws. Also the Pompilide with 
two cubital cells, which have hitherto been known as species of the 
genus Aporus, can, according to my ideas, be classed under the genus 
Pompilus, in spite of a peculiar modification of the wing nervures, 
which, after all, is unessential. The following is my division of the 
species into natural groups :-— 
ist Group (Pompzlus, Thoms.). 
The transverse medial nervure of the fore wing and the cubital 
nervure of the hind wing interstitial. Inferior edge of the claws 
toothed (one-toothed). Claw-brush generally developed. The tarsi 
of the anterior legs (in the female) with or without pectinated spines. 
Pesterior margin of the pronotum angular. 
2nD GRouP (Aporus, pt., Tab. IL, Fig. 7). 
By the loss of the 2nd transverse cubital nervure, diverging from 
the forms of the Ist group. In other respects resembling them. 
3RD GROUP. 
The transverse medial nervure of the front wing and the cubital ner- 
vure of the hind wing interstitial. Inferior edges of the claws toothed. 
Claw-brush wanting. The tarsal-brush (in the female), large. Posterior 
margin of the pronotum arched. Antennze short and remarkably thick. 
47TH GROUP. 
The transverse medial nervure of the front wing springs in or before 
the apex of the 1st submedial cell, the cubital nervure of the hind wing 
after the apex of the anal cell. Claw toothed ; claw-brush wanting. 
Tarsal-brush (in the female), large. Posterior margin of the pronotum, 
generally arched, very seldom angular. Antenne short and extra- 
ordinarily thick, 
OTH GRouP (Aporus, pt.). 
By the loss of the 2nd transverse cubital nervure diverging from the 
forms of the 4th group. 1n other respects resembling them. 
