24 ENTOMOLOGICAL NEWS. [January, 



cover it externally are those of the immediate neighborhood and 

 maj^ consequently be either sandstone or granite. 



The bees make their exit in the first two weeks of June, and 

 very soon after commence the construction of their cells, each 

 nest being, I believe, the product of one bee. The food is the 

 usual pollen-like mass of medium consistency, and I believe it is 

 simply deposited in the cell, as with other members of this family, 

 although in its habit of building this bee forms a strange and 

 unique contrast to its congener, Anthidiuin emarginaium, the 

 life-history of which I have already detailed in these pages. 



The larva, when mature, spins a cocoon, as shown in the illus- 

 tration; in form it closely resembles that of ^. evtarginatum, but 

 .is thinner, and of a somewhat transparent texture, with a promi- 

 nent nipple. The cell measures rather more than one-fourth 

 inch long by one-eighth inch wide; the nipple like projection is 

 one line long and touches the opposite wall of the cell, the larva 

 in consequence not filling the cell. The nipple is, as usual, on 

 the side nearest the outer wall of the nest. 



In making its exit the bee has a difficult task to accomplish, 

 and it is not a matter of surprise that it should sometimes be 

 unable to force its way through the tenacious mass of cement. 



From the contour of the point of exit I feel assured that the 

 exit is accomplished by the aid of a secretion that softens the 

 cement and allows the bee to force its way out. No fragments 

 were ever found that would indicate that the bees had gnawed 

 their way out, nor does it seem possible that such material could 

 be bitten through by a bee. 



The hymenopterous parasites afifecting this species are, on ac- 

 count of the usually exposed situation of the nests, probably 

 quite numerous, but so far only four have been discovered. The 

 most common of these is a small bee identified as Alcidamea 

 produda Cress., of which seven emerged in one instance from 

 one group of cells. Many of the other parasites were unable to 

 cut their way out, and were discovered dead in situ on breaking 

 open the cell. Of these, Monodontomerus montivagus Ashm. is 

 the most common. Leuco^pis affirds Say, was found once. A 

 new species named Torymus anthidii Ashm. occupied two cells. 

 Of the last there were twenty in each cell, the larvae having at- 

 tacked their host just after the cocoon had been spun. 



While collecting at Palm Springs on the Colorado desert in 



