1892.] 



THE BRITISH NATURALIST. 



183 



CCELIOXYS. 



Another parasitical genus, preying upon Megacliile and Saropoda. 

 Most of the species appear to be more or less promiscuous (always 

 within the limits of the above genera) in their parasitism. 



CcELioxYS, Latr. 



quadridentata, L. -conica, Thorns. — Formby, numerous, H.H.H. 

 elongata, Lep. — symplex, Nyl., Thoms. — Formby, HTI.H. ; 

 Southport and Cheshire Coast, B.C. ; Higher Bel)ington, 

 J.T.G.; Delamere Forest, E.C.T., R.N. 

 acuminata, Nyl. - One on Wallasey Sandhills, W.G. 



MEGACHILE. 



These bees are popularly known as " Leaf-cutters." They burrow 

 gregariously in various situations : in decayed wood, M . ccnfiDiailaris 

 and Willughhiella, in the ground, M. argmtata, circtmcincta, maritiiua ; 

 in the mortar of old walls, M. centiinculnris ; and in sound oak and 

 mountain ash trees, M lignesceca, The tunnels excavated in these 

 places they line with pieces of leaves most accurately and exquisitely 

 cut to fit the cavities from various trees and shrubs, more or less 

 according to species. No one species confines itself invariably to one 

 particular kind of leaf, nevertheless the undermentioned plants have 

 been observed to be selected most frequently by the following " Leaf- 

 cutters," viz. : — 



Rose by M centitncularis^ civcumcinda, and Wilhiglihiclln . 



Mercury by M civciunctiicta and centuiiciilaris. 



Elm by M . Lignesceca. 



Laburnum by M. Willughbiella and centuncnlaris. 

 Sallow by M. maritima. 



(To be continued J . 



THE DIPTEKA OF DORSETSHIRE. 



BY C. W. DALE, F.E.S. 

 [Continued from page 170.) 



88. Erioptera flavcsccns, Meig. Occurs on rushes growing m water 

 at Holwell and Middlemarsh, m tlie end of June and beginning of 

 July. 



89. E. macvophtJialnin , Loew. Common at Glanvilles \A'ootton in 

 July. This used to be confounded witli the last, which it much 

 resembles but it is rather a larger species and not of so deep a yellow. 



90. E. lutea, Meig.—costdlis. A local species. Occurs at 



