-44 rSKPTEMBKR 



the thorax is somewhat reddish, which is ]iroba})ly due to the immaturity 

 of the specimen. 



Q. TINCTORIA. Black Oak. Large^ round gall, somervhat attenuated 

 and jjoinfed at the top ^ surface more or less opaque, as if powdered or 

 dusted; shell thick; inside, a. dense, sjjongi/, IrrmrntsJi substance, surrrjvndine/ 

 the kernel. Diameter about an inch and a half. C. Q. spongifica 0. S. 



This is the opaque variety mentioned 1. c. p. 56, under the head of 

 Cynijys confluens. On the 25th of May last I found four full-grown spec- 

 iinens of this gall on the leaves of a large black oak (^. tinrtrrria), and 

 have obtained, on June 15, three 9 specimens of the gall-fly. They look 

 exactly like C. q. inaiiis, only they are a little larger, (the gall being also 

 larger) ; the three grooves on the back of the thorax seem to be deeper 

 and more distinct on their anterior portion ; the posterior part of the scu- 

 tellum, immediately behind the pit, seems to be more deeply and distinct- 

 ly excised ; finally, the punctation on the hind margin of the large (2nd) 

 segment of the abdomen is somewhat more distinct. 



Of these galls three, taken from a high branch of the tree, can be con- 

 sidered as typical specimens. They are slightly oblong, that is, somewhat 

 extended into a point at the end, although not narrowed at the basis. 

 Their diameter is about an inch and a half. Their color is drab, some- 

 times spotted with brown on one side ; the surface is more or less opaque, 

 as if powdered or sericeous, and shows very little gloss. The shell is 

 much thicker than that of the two previous species; the spongy mass is 

 more dense and brownish. 



A fourth specimen, found on the same tree, is more irregular in its 

 shape; its sui'face is without any gloss and altogether drab, without brown 

 spots. Specimens of this kind ai"e frequently found on young shrubs of 

 Q. tinctoriti, the leaves of which are very rusty-puberulent beneath. 



On a shrub of this kind, apparently also belonging to Q. tinctoria, I 

 found, liist June, three galls, resembling exactly those just described. I 

 cut them open iind obtained from two of them perfectly mature male 

 >^l>cc line IIS of Cynips; the third also contained a mature specimen, yet con- 

 tracted in the shape of a pupa and the abdomen of which was consumed 

 by parasitical hirvre.* 



There is no reason to doubt that the two males thus obtained, belong 

 to ('. q. spDiKjifca ; but if not for the circumstance that they were found 



* This fact i.-5 worth}' of romark, as it proves that some Icinds of 2iavasites be- 

 gin their attacks on\^ at a very hite stage of the development f)f tlie insect. 



