1891 ■] . 193 



sometliing over one irnn., and that of the case nearly two. By July 3 'th, the cases 

 were 3 J to i mm. long, for v.-ant of other material they were made of silk, frass, and 

 leaf chips ; the larva3 being fed on leaves of C. pratensis, which they cat freely. 

 They became apparently full grown in September, having cast their skins at least 

 twice. I lost them during the winter, having let them dry up. It may be desirable 

 to explain that the successive stages were not those of one individual larva, but of 

 specimens obtained at each date by opening a fresh pod, ao that the dates arc not 

 strictly accurate, if read for one individual, still, as all the egg laying is done in a 

 day or two, the different larvie must be very nearly of an age. 



I may also remark that in commencing my observations I was bothered by the 

 ova of a Curculio (I think) about the same size as those of rufimitrella, nearly 

 spherical, and laid, not in the cavity of the pod, but in the substance of the dissepi- 

 ment. In this ease just a trace of the place of oviposition is discernible externally. 



Firbank, Hereford: June, 1891. 



ON THE NESTS OF OSMIA BICOLOR, SCHK. 

 BT V. R. PERKINS, F.E.S 



In vol. xxi, pp. 3y and 67, of this Magazine, I drew attention to 

 what 1 considered was a very curious habit of Osmia hicoJor, Schk., a 

 h.ibit, I believe, quite peculiar to this one bee, that of [)icking up dry 

 bents of grass or stick, and flying away with them in its mandibles. 

 It is only the female that does this, and I concluded at the time I first 

 noticed it that it must have something to do with nidification, but in 

 what way I was at a loss to know. This bee is known to make use of 

 old shells of Helix nemoralis for its nidus. These it fills with its 

 cells, and I have seen the bee right inside the whorl of this shell 

 busily at work, and so captured it, but I have never seen any symptom 

 of stick or bent connected with it, so it was a puzzle what the bees 

 did with them. 



This present season, notwithstanding the very severe winter and 

 continued cold spring, these bees were out and about quite as early 

 and as numerously as usual, and by the middle of April they had 

 become plentiful. I was too much engaged with other matters at that 

 time to go and look after them, and it was on the 6th of this present 

 month that I was able to get away to one of the spots where these 

 bees can be watched attentively, and where I was not likely to be 

 disturbed. I found the females in abundance, and they were at their 

 old game, so now was my opportunity. I saw them alight on tlio 

 ground, search about and select a bent, and then fly off with it. I 

 was determined to solve the mystery, if possible, so I crept about on 

 my hands and knees watching intently the bees flitting along the dry 



