1864.] 591 



ber. Out of the 18. 6 or 7 had been bored hiterally by some minute 

 parasite, and from at least two of the recent ones parasites had perhaps 

 escaped at the terminal slit, for they contained neither larva nor cocoon, 

 and were unbored, although one of the recent ones was bored. Rare 

 near Rock Island, and difficult to discover from its simulating a short, 

 lateral twig. When these galls occur in great numbers on a twig, the 

 intervening buds perish, but when there are only one or two of them, 

 they do not. When the twig is .08 inch or less in diameter, the part 

 of it which lies beyond the galls shrivels up and perishes, even if there 

 be only one of them, but when the diameter is .13 or over and there is 

 but a single gall, it survives, at all events till the next season. 



Larva. — Sanguineous with yellow bowel-like markings, about .08 inch 

 long and .04 inch wide ; breast-bone as in C. s. hrassicoides. but as in 

 some varieties of that species, with the posterior arm of the Y only about 

 J as long as each anterior arm, and terminating behind in a square trun- 

 cation. The cocoon is described under the head of the gall. One spe- 

 cimen, found in November. 



Pupa and imago unknown. 



No. 8. Gall s.siliqua. n. ST^.l=Salicis? Fitch^rigidoe / Fitch, 0. S. — On S. hu- 

 milis (and also on S. cordata? and S. discolor?) A monothalamous, solitary, 

 oval or subspherical. woody gall, .55 — 1.00 inch long and .20 — ..34 inch in diame- 

 ter, growing at the tip of a twig, frequently with several twigs apparently of the 

 same year's growth surrounding it, tt pared at tip to a short, blunt, tubiliform 

 beak, which is evidently a deformation of the terminal bud, and hollow inside. 

 The outside surface of the gall, which is the natural color and texture of the 

 bark of the twig, always contains, besides the terminal beak-like bud, 2 — 5 

 buds, which are still alive in November in the recent gall but afterwards perish 

 along with the gall itself, as does also, unless the twig on which the gall grows 

 be large, a portion of that twig. Sometimes one of these external buds sprouts 

 out into a twig, growing from the outer surface of the gall, and in a single spe- 

 cimen there are four such twigs. The walls of the internal cell or hollow, in- 

 cluding the bark, are .06 — .11 inch thick, and lined when mature inside with 

 the cocoon of the gall-maker, which is detached and of the usual delicate tex- 

 ture towards the tip of the hollow, so as to form a kind of diaphragm to exclude 

 any air that might enter through the terminal beak, but is agglutinated strongly 

 to them everywhere else, though it may be detached piece-meal, generally with 

 a thin layer of the greenish woody matter adhering to it. The internal surface 

 of the terminal beak is smooth, continuous with that of the main c. 11 or hollow, 

 and not strongly pubescent at tip as in <S'. cornu ; on its external surface there 

 is the natural suture at its base. In one specimen, where a large, abnormal, 

 woody wart had been formed about the middle of the hollow, the larva, instead 



