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analogous to the fact of many of the Lepidoptera feeding upon different plants. 
We cannot, it is true, yet trace it to any known law; but it is not enveloped in 
greater obscurity than the other well-known circumstance, also corroborated in 
some of the above observations, of several species, and even genera, of parasites 
feeding upon the same insect. The most extraordinary instance adduced above 
are those of Mesoleptus , Tryphon , and Paniscus feeding upon Tenthredinidce . 
Could some parasite be found to infest Athalia spinarum , the agriculturist might 
then hope for a permanent check to one of his greatest enemies ; but we are sadly 
afraid that the mere acumen of Entomologists will never elaborate an effective 
remedy for the devastation amongst turnips until nature lends her help by the 
abundant propagation of a destructor of the destroyer in the shape of an insect 
parasite. 
The authors, also, partially characterize a new genus (Gravenhorstia) for 
the reception of a new insect, allied to the Ophions , developed in May from the 
pupa of Bornbyx Trifolii: as this moth is common with us, the Ichneumon may 
also be found, and we therefore give the characters. 
Gravenhorstia.— Boie. 
Head with four impressions on the face beneath the antennae, placed in pairs, 
the two upper ones half-moon shaped, and between them a small tubercle. An¬ 
tenna of the length of the abdomen. Scutellum very convex, triangular or sub- 
quadrangular. Wings short. No cell . Posterior legs long; tarsi incrassate. 
Abdomen petiolated, as long again as the thorax, laterally compressed, enlarging 
towards the apex. Ovipositor scarcely exserted. 
G. picta , B.—Black. Face and orbits of the eyes yellow ; tubercle of the 
face, black. Antennce reddish yellow, the two first and fourth joints black above. 
Thorax very convex, punctured, opaque, pubescent, with twelve yellow spots, of 
which two large triangular ones on the prothorax, one on each side, two smaller 
ones in stripes before and beneath the wings on each side, and the six others as 
large as the first beneath the coxae, which are very shiny. Scutellum also yellow. 
Wings yellowish with brown stigma. The anterior and intermediate legs of a 
brownish yellow; and the posterior pair, with the femora and apex of the tibiae, 
brown. The Abdomen shining, with seven broad yellow bands placed on the mar¬ 
gins of the segments. Length from eight to ten lines; females larger than the 
males. Habits resemble those of Ophion. 
The next article is a Systematic Investigation of the Family of the Bostri- 
chidce, by Dr. Erichson, a name which ensures the value of the monograph from 
being so advantageously known as that of the author of the genera Dyticeorum, 
an inaugural Dissertation, and the Paper upon the Histeroides of the Berlin 
