94 
DIPTERA. 
covered by Mr. Fichtel, who, he adds, has thus established the habitat of this singular 
creature beyond dispute. 
Linnaeus, to whom only an individual species of Diopsis was known, as usual with 
him under such circumstances, does not assign to it any specific character. Donovan 
states that he was acquainted with another species of this genus, a native of Africa, in 
the collection of T. Marsham, Esq. which rendered a deviation from his example 
excusable, although the latter was at the time undescribed. 
Since the preceding observations by Donovan was written, great additions have 
been made to this curious genus. Fabricius, like Donovan, adopted the Linnaean 
specific name ichneumonea, but confounded under that name two species distinct from 
each other, and from the original species. Illiger added another species, D. nigra. 
Dalman described three new African species; Weidemann another, which he named 
in honour of Dalman; and Gray another, D. Sykesii, in Griffith’s Animal Kingdom. 
More recently, in the seventeenth volume of the Transactions of the Linnaean Society, 
I have published a monograph upon the genus, in which I have described thirty-one 
species, giving coloured figures of the greater portion. All of these species, (with the 
exception of D. brevicornis of Say, which belongs to a distinct subgenus,) are natives 
of the old world, inhabiting Guinea, Sierra Leone, Senegal, the Cape of Good Hope, 
Arabia, and the East Indies. 
In this monograph I have endeavoured to prove, that Guinea, or the adjacent 
parts of Western Africa, is the true locality of D. ichneumonea; whilst Donovan’s 
species, which belongs to a distinct section of the genus with the spot on the wings 
terminal, (and not merely a sub-apical fascia, as in D. ichneumonea,) I have given as a 
distinct species, under the name of D. Indica. 
