216 



PS7'CHE. 



[May— July iSS6. 



crowded together. The galls resemble 

 verv much the galls of Holcaspis duri- 

 coria Bass. {Cynips mamma Wal.) 

 (Fig. 3). The galls are very much the 



Fig. 3. 

 shape that a thick waxy material would 

 take if dropped on the twigs and then 

 suddenly congealed, leaving stout, teat- 

 like projections standing out from each 

 drop. The central cell is placed low in 

 the gall and can usually be seen protrud- 

 ing when the latter is broken off. Some 

 entomologists have thought this gall to 

 be Identical with Walsh's C mamrna^ 

 but I have examined a large number of 

 both forms and the following points 

 of difference, which convince me that 

 this, if not not a new species, is certainly 

 a well marked variety : 



H. bassetti as compared with H. 

 duricoria^ is rather larger and is more 

 irregular in outline. The teat-like pro- 



jection is much heavier and longer in 

 proportion to the size of the gall and 

 appears to be a drawn-out portion of the 

 substance of the gall, while in dtii'icoj'ia 

 it is a small, hard pointed projection 

 much resembling a spine in many cases, 

 and often almost entirely wanting. In 

 bassetti the substance of the gall is more 

 corky and easy to cut. The central cell, 

 as before stated, is at the base of the 

 gall, and when the latter is removed the 

 point of the cell can usually be seen pro- 

 truding below. Before the gall is de- 

 tached the central cell is situated with 

 its greatest diameter perpendicular to 

 the limb at the point of attachment of 

 the gall. In diiricorla the cell is situ- 

 ated at the centre of the gall ; it never 

 protrudes from below when the gall is 

 detached ; and it always has its greatest 

 diameter parallel with the limb at the 

 point of attachment of the gall. The 

 central or larval cells are also different- 

 ly shaped. In ditricoria the cell is 

 egg-shaped, while in bassetti the end 

 towards the tv\ ig is somewhat pointed, 

 so that the cell is very much the shape 

 of a plump apple seed with the point 

 rounded off. 



Gall-fly : Female. Median line of 

 the face black, the black portion being 

 broadest between the eyes ; vertex dark 

 brown to black ; occiput black ; orbits 

 and genae cinnamon brown ; clypeus 

 and lower border of epicranium black ; 

 mandibles black at base and tip, with 

 the median portion brown ; palpi a light 

 amber color, with the terminal joints of 

 the maxillary palpi infuscate ; and all 

 joints set with gray hairs. The epicra- 



