CECIDOMTIA. 191 



1-8. On hickories ( Gary a) of different kinds. 



The numerous galls of Cecidomyice occurring on the hickory are 

 found indifferently on the various species of this tree. I have 

 noticed also that whenever a spot is found where one of the galls 

 occurs in abundance, some of the other kinds are sure to be found. 

 Thus the galls of Gee. holotricha and those of Diplosis caryce, or 

 those of the latter with the galls of Gee. tubicola are frequently 

 met with on the same leaflet. 



These galls may be distributed as follows (the numbers from 1 to 

 8 corresponding to those of the descriptions given below): A. True 

 galls, fastened to the under side of the leaf and breaking off easily. 

 a. Bare. 1. Subglobular, with a small nipple at the tip, diam. 

 0.05 to 0.1. 2. Elongated onion shaped, a little larger than the 

 preceding. 3. Conical, contracted at base, blood red or purplish. 

 4. Cylindrical, erect, inserted in a cylindrical socket, b. Pubes- 

 cent. 5. Subglobular, with a nipple at tip (or short onion shaped), 

 pubescent with ferruginous. 6. Subglobular, without nipple at 

 tip, finely downy. B. Other deformations. 7. Swelling of the 

 midrib at the base of the leaf. 8. Yellow spots on the leaves; 

 larva living on the leaf, not within it. 



1. Diplosis caryce 0. S. Gall Subglobular, smooth, seedlike, 

 0.05 to 0.1 in diameter, with a small nipple at the tip. In sum- 

 mer they are yellowish-green and their shell is soft; in winter they 

 become brownish, and the shell, although thin, is hard and woody. 

 They begin to grow in June. I gathered them in October, when 

 the larva was full grown. 



Each gall contains a single larva; it is white, and stouter in 

 proportion to its length than most larvae of Cecidomyia. The 

 breast-bone has two sharp points anteriorly, with an excavation 

 between them; the tip of the last abdominal segment has no horny 

 processes. It undergoes the transformation within the gall. The 

 pupa resembles, by the structure of its head, that of C. saroihamni 

 Wz., figured by Mr. Winnertz in his monograph (I. c. tab. I, f. 6); 

 namely, the .pointed projections at the basis of the antennae are 

 closely approximated and not remote, as in other species. 



After having kept these galls on moist sand all winter, I ob- 

 tained the fly in April. (Description drawn from a fresh specimen.) 



D. caryae 0. S. < and 9. Antennae pale; 26-jointed; 

 alternate joints a little larger than the intermediate ones; verticils 



