42 Rev. F. D. Moiice on vudc terminal segments and 



to suit all that is said by either author quite as well as 

 the present. 



Radoszkovvski's halteatus is certainly marginatus, Smith, 

 and I believe Thomson's is the same. 



In its armature and seventh ventral segment the present 

 insect resembles very closely the four species next to be 

 figured. But it differs in that the stalks or petioles from 

 which the lobes of the seventh ventral plate spring are 

 evidently pilose. They have a continuous ciliation of 

 Avell-developed hairs, proceeding from definite punctures, 

 which commences nearer the base of the segment than 

 the point at which the lobes begin to spread from it. 



In the armature all five species agree (a) in the narrow 

 elongate un-notched stipites, which contract very gently in 

 the dorsal aspect, but rapidly in the lateral (PI. IX, 64), to 

 form the slender and very pilose apical process; (b) in the 

 manner of folding (rather than the actual outline which 

 depends on a variety of accidents) of the dilated sagittse. 

 The more transparent part of this (the " fourreau ") 

 consists of tvjo laps (one basal, the other apical) which 

 'partly cross each other, and in so doing produce the effect 

 of a triangular sub-opaque thickening of the membrane. 

 These laps are further overlapped by a third fold which is 

 ckitino'us and triangular, occurring at the point where the 

 sagitta3 (viewed laterally, PL IX, 64) are bent downwards 

 almost at a right angle, and this is really about half-way 

 between their bases and their apices, though in the dorsal 

 view the deflected apical halves are so foreshortened that 

 this is not easily realized. Between the bases of the 

 sagittce and the stipites the volsella peeps out, of coirrse 

 at a much lower level, and therefore only to be seen 

 properly by altering the focussing. 



All this group agree as to the seventh segment in the 

 gradual dilatation of sub-triangular and petal-like lobes 

 from elongate stalk-like and apically sub-acuminate in- 

 terior " costa3." The clouding, etc. of these lobes is also 

 very similar. They differ chiefly in their degree of dilata- 

 tion (more or less rapid) and in the outline of their actual 

 apical margin, to see which properly, however, the object 

 must be viewed in more aspects than one. 



In external characters they agree in being all very 

 shortly haired on the discs and conspicuously banded at 

 the apices of the segments. The fascia? are entire, and 

 there is usually — perhaps always — a distinct basal fascia 



