6612 Insects. 



the supposed male, which I now find to belong to P. hyalinatus. Mr. 

 S. Stevens took both sexes in Sussex, but I never suspected their 

 affinity. Tn the Kirbyian collection I had seen the male, which the 

 monographist himself had united to the species without any remark or 

 indication of doubt, so that nothing but positive observation, proving 

 him to have been mistaken, could have warranted me in differing from 

 so high an authority. The fact of the male of P. hyalinatus being 

 identical with that given as that of Kirby's P. annularis, had escaped 

 my observation. 



The cells of Prosopis dilatatus, which I found at Pakefield, in Suf- 

 folk, were constructed in the dead stem of some umbelliferous plant ; 

 the parent bee had formed a burrow five inches in length and one in 

 diameter, the tube being lined with a delicate colourless transparent 

 membrane ; each cell was four lines in length, and separated from the 

 next in succession by portions of the excavated pith ; the cells were 

 seven in number, six only being provisioned and closed ; the food 

 stored up consisted of semiliquid honey. In a few days the young larva 

 appeared, and at the expiration of about ten days were full fed and 

 entered upon a lethargic state, in which they continued from July, 1858, 

 to May, 1859 ; at the beginning of the latter month they assumed the 

 pupa state, and gradually progressed to the imago or perfect condition ; 

 two males were developed on June 10, two females on the 15th, and 

 two on the 16th. Had the bee completed her task before I discovered 

 the nest, in all probability the number of males would have equalled 

 that of the females. 



The economy of this genus w r as first discovered by Mr. Thwaites in 

 1841, previous to which they were considered to belong to the para- 

 sitic division of the Apidaa ; since that period I have bred P. communis, 

 P. dilatatus, P. signatus and P. hyalinatus. All the species usually 

 burrow in the stems of dead plants, bramble, sticks, &c. ; but some of 

 the species at times deviate from the usual course : thus P. signatus 

 occasionally burrows in the mortar of old walls, and I once had 

 a hollow stone given me which contained cells of P. communis. 



In conclusion, I should observe that the spots described as yellowish 

 white in the ' Monograph ' are snow-white in specimens when first 

 developed. The Prosopis variegata has not been captured, to my know- 

 ledge, since Dr. Leach is supposed to have taken it at Kingsbridge, 

 Devonshire ; and the correctness of keeping it in the British list 



requires confirmation. 



Frederick Smith. 



