igio] Anatomy of Cecidomyia resinicoloides 55 



first pair of spiracles, and posteriorly to near the anus. It is 

 circumscribed and largely supported by the tracheal system. 

 Some time before pupation this fat tissue loses much of its com- 

 pactness, becoming more or less watery in appearance and 

 assumes a reddish color. 



hnaginal Discs of Wings and Legs. Plate VIII, Figs. 6 and 7. 

 These are easily seen in large full-fed larvae where they appear 

 as more or less circular discs attached to the body wall. 



The wing-buds, PI. VIII, Fig. 7, A2A3, are larger than those of 

 the legs, lie very slightly above the lateral line of the body, and are 

 supplied with branches of the lateral and dorsal tracheae. Both 

 wing- and balancer-discs arise from about the middle of their 

 respective segments, ending posteriorly in a lobe and tapering 

 anteriorly into the body wall. 



The three pairs of leg discs. Fig. 6 Ai, A2, A3, are situated on 

 either side of the ventral line and are more distinctly circular 

 in outline than the wing discs and more strongly and completely 

 cut by an inner ring. They are supplied by small branches of 

 the lateral tracheae. 



BIBLIOGRAPHY. 



1. Aldrich, J. M. (1905). Catalogue of N. A. Diptera, pp. 151-152, 



KiO. 



2. Berlese, A. (1900). Sistema Ghiandolare, Ghiandole Confinate, 



(Gli Insetti, I, p. 523). 



3. Comstock, J. H. (1879). Diplosis resinicola, (Rept. Dep. Agr., 



1879, p. 256). 



4. Cannon, W. A. (1900). A Botanical Study of the Gall formed 



bv Diplosis pini-radiatae, (Am. Nat., X'XXIV, No. 406, pp. 

 801-810.) 



5. Eckel, L. S. (1903). The Resin-Gnat Diplosis and Three of Its 



Parasites, (Ent. News, XVI, pp. 279-284). 



6. Felt, E. P. (1903). C. resinicola, (N. Y. State Mus. Memoir 8, 



II, pp. 410-413.) 



7. Felt, E. P. (1903). C. pini-rigidae, (N. Y. State Mus. Memoir 



8, II, pp. 423-425). 



8. Giard, A. (1893). Note sur I'organe appele Spatula sternalis 



chez certaines larves de Cecidomyes. (Bull. Ent. Soc. France, 

 Feb. 22, 1893). 



9. Giard, A. (1893). Sur un genre nouveau et une espece nouvelle 



de Cecidomvidae (Drisina glutinosa), (Bull. Soc. Ent. France, 

 Dec. 27, 1893). 



