1864.] ' 689 



sting of the insect causes the huds that would otherwise remain unde- 

 veloped till the following year, to develop in the autumn in the abnor- 

 mal manner described above. 



The rudimentary leaves are green, ligulate. and the more perfectly 

 developed galls resemble, more than anything else I can think of, the 

 flowers of the common Artemesia of the flower garden. They are not 

 common, but T have several times met with them, and the clump of oak 

 bushes from which my specimens were gathered was covered with them. 

 The larvae are now fully grown. On the same bushes I found a gall 

 like (J. q. gJobidua Fitch, — and several dry, brown galls on the petioles 

 <tf the leaves, apparently those of C. q.petiolkola. 



Q. RUBRA. Clusters of seed-like bodies, often thirty or forty toyi- 

 ther i] rowing on the tnidvein on the under side of the leaves of Q. rubra. 

 The larger eells are about the size of a grain <f wheat. They are 

 smooth, greenish-white^ the apex enlarged, and would remind a brjtanist 

 of the sessile stigma of some flowers. — C. Q. DECIDUA, n. sp. Gall fly 

 unknown. 



My specimens were collected about the first of October, and were 

 then fully grown. 8ome had fallen to the ground, but on cutting open 

 a large number I could not detect any larvae. The leaf stems and twigs 

 were placed in water to keep them green, but the galls soon dried and 

 many fell off". A few fell into the water, and these not only kept green, 

 but on opening them a few days since, half-grown larvae were found. 

 From this I infer that the growth of this species is dependent upon the 

 galls being covered in the earth. 



Gen. DIASTROPHUS. 

 DiASTROi'HUS PoTENTiLL^, u. sp. Gralls On Potentilla Canadensis. 

 They are from .3 to .5 of an inch in diameter, and rather longer than 

 thick, growing in the axils of the leaves ; of a soft spongy consistence 

 when dry, and each contains a single cell in shape and size like the nu- 

 cleus of C. q. globulus, though not, like that, free from the substance 

 in which it is enclosed. They are rather rare here (Conn.), but I saw 

 large numbers of them in the northern part of Berkshire Co., Mass., 

 last summer. The fly came out May 20th from galls of the previous 

 year's growth. It is much like D. nebulosus 0. 8., but Baron Osten 

 Sacken has compared it with this species, and pronounces it distinct. 



