222 
thinks that dilatata, Er., is probably another synonym of it, he 
also overlooking the existence of P. atomaria, Oliv. Under these 
circumstances it seems perhaps best to take provisionally the 
oldest of the names that have been regarded as synonymous and 
to call the insect dilatata, Er., until some reason be produced to 
the contrary. Atall events atomaria, Marsh., cannot stand. 
Thus corrected, Dr. Chapuis’ Catalogue of Group I. contains 
the names of 27 species, and of these I have more or less reliable 
types of 25—some few of them identified by description, and 
most of them represented by types from Chapuis. ‘The two that 
I do not know are nigroscutata, Chp., and formosa, Chp.; the 
former of these is insufficiently described and may possibly be 
my montana or debilitata ; formosa I feel confident that I have 
not seen. 
Dr. Baly’s descriptions of the 11 species of this group that 
bear his names and his re-descriptions of the eight other species 
dealt with in his paper referred to above are in most respects 
very satisfactory, but two remarks regarding them seem called 
for—the one, that they include as main characters the form of 
internal sexual organs, which, requiring dissection for examina- 
tion, are obviously not easily available to the student (I have 
omitted all reference to these organs in my descriptions, from 
want of material for dissection); the other, that Baly’s state- 
ments of the comparative length, breadth, &c., of prothorax, 
elytra, &c. are very unreliable, being evidently not founded on 
measurement ; thus that author makes the prothorax of many 
species three times (or even more) as broad as loug, whereas I 
have not seen any Paropsis (at any rate of Group I.) whose pro- 
thorax by measurement *& even very nearly three times as broad 
as long, though to a casual glance some appear so ; and again, the 
proportion of the length of the elytra to their breadth is always 
over-stated by Baly, those organs appearing to the eye consider- 
ably longer as compared with their width than actual measure- 
ment shows them to be. One of the species (P. suspiciosa) dealt 
with by Baly is not a member of Chapuis’ Group I. 
Although the species of Paropsis forming this group are for 
the most part very satisfactorily distinct inter se, and unlikely to 
be reduced in number by subsequent investigation, their dis- 
tinctive characters are by no means easy to specify sufficiently 
clearly in words for confident identification—often consisting in 
differences of form or of sculpture that it is difficult to express 
definitely. Consequently J have found it necessary to adopt a 
system of indicating the measurements with exactness, as I find 
these very constant in either sex of each species. It will be 
necessary then to explain—first, that by the “height” of a species 
I mean the distance (the insect being so regarded that the suture 
