294 Mr. Westwoop on Diopsis, 
such had been the case, because he did not overlook the difference in colour 
of the thoracic spines. Further, the engraving ought not to be too much 
relied upon, since the base of the abdomen is nearly as darkly coloured as the 
terminal segments, and, as Dalman observes, the 4th and 5th longitudinal 
nerves are represented as running in a straight direction to the margin of the 
wing. In the last place, Dalman describes the halteres as * pallidi," Mos 
Linneeus is silent as to their colour. 
I have been thus minute in noticing the characters of this species, not only 
because it is the original and typical insect in the genus, but also because 
upon the elucidation of its distinctions depends the specific rank of one, if not 
of two, of the other species which I have given. D. Ichneumonea does not 
exist in the Linnean cabinet; the only species contained therein being that 
which I have named D. obscura, and which totally disagrees with the Linnzean 
description. ( 
The doubts which exist respecting the charations of this species are more- 
over increased by those concerning its real habitat. Linnzus merely says; 
* Inclitissimo Lond. Anglorum Medico Dom. Doctori Fothergill, qui naturze 
pervestigationem in summis habet deliciis, et maximam insectorum copiam, 
precipue ex America septemtrionali et Guinea allatam, possidet, ad Nob. Dom. 
Praesidem excellentissimas suas collectiones, haud ita pridem, mittere placuit." 
The introduction of the word * przecipue” at once shows that the insects in 
Dr. Fothergill’s collection were not exclusively from North America and 
Guinea, as recorded by Dalman and Wiedemann. Fuessly (according to 
Donovan) upon this ambiguous authority describes the insect as a native of 
Cayenne; Gmelin notes it as inhabiting both Guinea and America; Fabricius 
(probably, however, confusing three different species,) mentions Angola, Su- 
matra, and Congo; Latreille, on the authority of M. Perrin, a zealous natu- 
ralist of Bourdeaux, states it to be from the coast of Angola*; Donovan (evi- 
dently, however, speaking of a distinct species, notwithstanding his positive 
* Latreille, in the Dict. d' Hist. Nat., published an original description of the specimen brought 
from Angola by Perrin. He describes it as 5 lines long, with the head “fauve,” thorax black, ab- 
domen *''fauve," with the two last segments black, wings “avec un point noirâtre vers l'extrémité ;" 
thus confirming the Linnean description in every particular, as well as establishing its locality as an 
African insect. 
