the insect introducing her intrusive progeny to evade the instinctive apprehension of the laborious mother, and nature has furnished additional means to foil the latter, in the parasite's resemblance to herself." This, Mr. Shuckard observes, "appears plausible, but it is not yet substantiated, nor is it general;" and certainly Coelioxys is an instance of great discrepancy between the two insects. Now, I would observe that in the case of a solitary bee, like Saropoda, I do not see that a resemblance could be of any great service to the parasite, for I doubt not the bee would repel the intrusion even of one of her own species; and where the nests are left without any sentinel to guard them resemblance is unnecessary. But the case is different amongst the social Hymenoptera; and here we find the resemblance complete, as between Apathus and Bombus, and even of the Diptera parasitic on them the resemblance is very close, as between Bombus terrestris and Volucella bombylans, but I cannot call to mind any very strong similitude amongst the solitary species and their parasites. I this year bred Nomada Schæfferella from the cocoons of Eucera longicornis, between which there is a vast discrepancy; as there also is between Andraena fulva and Nomada ruficornis, which I have seen entering its burrows, and have no doubt is its parasite; and to instance but one more, Chrysis dimidiata and Epipone spinipes.
Much of the history of these Hymenopterous parasites still remains a mystery. Do the bee and the parasite both deposit an egg in the same store of food? This I should infer must frequently be the case, nature has therefore wisely provided that the parasite shall be first extruded from the egg, when it consumes the store provided for the bee, which consequently perishes. This inference I have no doubt is correct, as I dug up a number of the cocoons of Eucera longicornis, and on opening some of them I found two specimens of Nomada Schæfferella perfectly developed and active, whilst the Eucerae, in many instances, appeared to have but recently changed to pupae, and did not attain their perfect state until the beginning of June. I shall probably at a future opportunity refer to the interesting subject of parasite bees. During the last seven years, whilst assiduously collecting, I have carefully investigated the habits and economy of this interesting family, and hope my notes and observations made during that period may prove acceptable to the readers of 'The Zoologist.'
Cœlioxys umbrina.—Dark brown: abdomen with five uninterrupted fasciae: the face covered with longish pale fulvous hair; the mandibles and cheeks with silvery hair: thorax densely clothed with fulvous hair above, and with silvery hairs beneath; the scutellum has
