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of the elytra is in its upper outline and the lateral margin is in 
its lower outline and the humeral angle seems directed down- 
ward) from the highest point of the upper outline to the lower 
outline, 7.e., the length of that portion of a pin passing from one 
to the other of these points, which would be in the body of the 
insect ; second, that the length and breadth of the elytra is 
ascertained on the undersurface, the length being the length of a 
line from the apex of the elytra to the point where a transverse 
line from shoulder to shoulder intersects the longitudinal middle 
line of the insect (usually on the prosternum), the breadth being 
the greatest distance between the lateral edges of the elytra; in 
measuring the breadth allowance must be made for any displace- 
ment there may be of the elytra. It is impossible to measure 
either length or breadth of elytra reliably on the upper surface 
owing to the great convexity of those organs. 
After long and careful consideration, I have been unable to 
make use of the external sexual organs as specific characters. 
They are exceedingly well marked inter-sexually, consisting in 
the shape of the tarsal joints, the length of the antenne and the 
form of the apical ventral segment, and in some species in the 
outline of the body—but they do not vary much specifically. 
While this undoubtedly increases the difficulty of distinguishing 
species, it removes the objection to describing species on the 
characters of one sex alone, as it is easy to judge with tolerable 
certainty what would be the characters of the other sex. This 
remark has reference merely to Group I. of the genus; in at 
least one of the other groups there are species in which sexual 
characters seem more important. 
In the following table will be found the distinctive characters, 
then, of 46 species, which is the total number known to me to- 
day as attributable to Dr. Chapuis’ first group of Paropsis ; viz., 
25 enumerated in Dr. Chapuis’ Catalogue, three since described 
by myself, and 18, of which the descriptions are furnished below. 
Tabulation of those of the described species of Paropsis whose 
elytral puncturation is entirely confused (‘Group I.” of 
Chapuis) :— 
A. Front angles of prothorax mucronate. 
B. Sides of prothorax not (or scarcely) bisinuate. 
C. Scutellum deep black. 
D. Prothorax more than twice as wide as 
long 7 Larry, Baly. 
DD. Prothorax not more than twice as wide 
as long. 
E. Dise of elytra with raised wart-like 
inequalities .. Lownet, Baly. 
EE. Disc of elytra devoid of wart. like 
inequalities. 
F. Puncturation of elytra moderately 
close (as in P. Lownei) ... ... montana, Blackb. 
