20C. HYMENOPTEKA. 



teinue is minute, and the liind femora are thick, but not ser- 

 rated, and beneath armed with a tooth near the tip. 



The wings are rudimentary so that it does not quit the cell. 

 Newport states that the larva is fiat, yen- hairy, and spins a 

 silken cocoon when about to pupate. It is an ''external feed- 

 ing parasite" consuming the pupa as well as the larva of An- 

 thophorabia. The imago appears about the last of June, 

 perforating the cell of the bee. Jt also lives in the nests of 

 Osinia, Anthophora, and Odynerus. 



The genus Anthopliorabia is so-called from being a parasite on 

 Anthophora. The males differ remarkably from the females, 

 especially in having simple instead of compound eyes, besides 

 the usual three ocelli. ^1. mw/itchilis Pack. (Plate 3; tig. 7. 

 larva; IK. pupa) is a parasite on a species of Megachile. 

 The larva is white, short and thick, cylindrical, with both 

 extremities much alike ; the segments are slightly convex, and 

 the terminal ring is orbicular and rather large. Length. .04 

 inch, being one-third as broad as long. On opening the cells 

 of Megachile, we found nearly a dozen containing these para- 

 sites, of which l."iu larva? were counted clustering on the out- 

 side of a dead and dry Megachile larva. In England they 

 occur, according to Newport's observations, in much less num- 

 bers, as he found from thirty to lifty in a cell of Anthophora. 

 A few females hatched out in the middle of October, and there- 

 were a, few pupae left, but the majority wintered over in the 

 larva state, and a new and larger brood appeared in the spring. 



J'crtlfiitipiis is a beautiful genus, with its shining, metallic 

 tints. The eleven-jointed antenna; are short, lying Avhen at 

 rest in a dee)) frontal furrow. The head is large, while the 

 abdomen is slightly pedicelled, being short, contracted, with 

 the ovipositor concealed. P. pldtiiyuxtcr Say and /'. triamjit- 

 /((//.s Say were described from Indiana. 



The numerous species of Pt< j ro)iialnN often oviposit in the 

 larva* of butterflies. In this genus the antenna? are inserted 

 in the middle of the front. The abdomen is nearly sessile, ob- 

 tusely triangular, or acutely ovate in form, with the ovipositor 

 concealed. The femora are slender. There are about three 

 hundred species known to inhabit Europe. Ptcromalus >- 

 Harris is a parasite on Vanessa Antiopa. P. rlisio- 



