OF CERTAIN CHALCIDIDZ AND ICHNEUMONIDE. 65 
having “singularly distorted antenne, and the wings almost rudimental,” thus offering, 
he says, “ a strikingly opposite analogy to other bee-parasites.” But without describing 
M. Audouin’s insect, either generically or specifically, or explaining in what its “ stri- 
kingly opposite analogy” consists, this naturalist has proposed to designate that insect 
Melittobia Audowinii. A name thus given without a description, either generic or spe- 
cific, cannot, however, be adopted; even if that insect should ultimately prove to be iden- 
tical with mine. The necessity for precise description when a name is imposed will at 
once be perceived, in the fact that both Reaumur and DeGeer long ago found Chalcidi- 
dous parasites in the nests of mason-bees, and yet, up to the present time, their species 
have not been clearly made out. Reaumur * found more than thirty larve of one species, 
and in other nests ten or twelve of a larger species. DeGeer + also found twenty speci- 
mens of another kind. in a single cell, and which he reared to the perfect state. He re- 
marks, too, that the larvæ of mason-bees are very subject to be destroyed in their cells by 
the larvæ of different species of Zchneumon. The species found by DeGeer seems to have 
been a Pteromalus, or nearly allied to that genus. These facts are interesting, as showing 
that mason-bees are infested by many parasites. The occurrence of Audouin’s insect in 
the nest of Odynerus, as well as of Osmia and Anthophora, as stated, renders its identifica- 
tion with the insect I have discovered very doubtful. I have never found my species in 
any other than the nests of Anthophora. 
The habits of this insect may be inferred from the peculiar organization of the male. 
From both sexes being found in the closed cells of the bee, and from the absence of a long 
ovipositor in the female, we may conclude that the eggs are deposited while the nest is 
being provisioned, or immediately before it is closed; and that, like the true Ichneumons, 
the parent either plunges her eggs into the body of the newly-hatched bee-larva, og 
attaches them to its skin. The bee-larva, like many other species similarly arcum- 
stanced, continues to feed, and grow, and supply nourishment to the parasites; and by 
the timé it has consumed the whole of its provision, these also are far advanced in growth. 
When the young bee is entirely destroyed these are matured, and pae for their change 
to the state of nymph, which they assume lying loosely in the cell, without spinning sepa- 
as rn tance that although both sexes are found moving about freely in the 
cell, the male is by far the least active, and especially from the fact that his organs of 
; instead of large compound eyes, as in the other sex, I am 
| led to the conclusion that impregnation is effected before the insects quit their habitation ; 
because ocelli, being different in their structure from the individual parts of the — 
pound eyes, are fitted only for near vision. The difference of structure consists in this: 
the ER, external surface of each part of the compound eye, which a mad " 
perfect, as an organ of vision, as the ocellus, or ee en 
of the latter; while the chamber of the eye, or space between the cornea and the termina- 
tion of the nerve at the bottom of the structure, is of much greater length in the com- 
vision are merely single ocelli, 
* Mémoires pour servir à l Histoire des Insectes, gene part. i. p. 98. 12mo. Amsterdam, 1748. 
+ Mémoires, tome ii. part. 2. p. 887-8. pl. 30. fig. . 
YOL. XXI. 
E 
