SVRI'IIIDAK Ol' MAIM',. 26 1 



plate (q. v.) ; usually straight or slightly curved but often sinuate, 

 convoluted or undulated, and may bear lateral projections or denticles. 

 They usually radiate and are usually elevated on cariiue. 'I hey are 

 named dorsal, median and ventral pairs the former usually nearest 

 the circular plate. 



Spiracle: An opening to a trachea, or breathing pore. See anterior 

 larval spiracle, slit-like spiracle, stigmata. 



Stigmal plate: Either half of the truncated apex of the posterior 

 respiratory process, usually separated from the other lateral half by a 

 distinct median dorse-ventral incision. It bears three slit-like spiracles 

 (q. v.), the circular plate, and the interspiractilar ornamentation. 



Stigmata: See spiracle, pupal respiratory cornua. 



Ventral line: The margin of the puparium, when viewed from the 

 side, extending from the position of the larval mouth-parts in front, 

 along the venter to the base of the posterior respiratory process at the 

 posterior end. 



Ventro-lateral carina: An irregular, longitudinal, fleshy ridge along 

 the side of the body of the larva underneath the dorso-lateral carina 

 and bearing the lateral segmental bristles. 



BIBLIOGRAPHY. 



1. ALDRICH, J. M. Catalog of N. A. Diptera, Smithsonian Miscella- 



neous Collections, No. 1444, 1905. 



2. AUSTEX, E. E. British flies which Cause Myiasis in Alan. Reports 



to the Local Govt. Board on Public Health and Medical Sub- 

 jects, New ser. No. 66, 5-15, 1912. 



3. BAKER, CARL F. Biological Notes on Some Colorado Diptera, Ent. 



News, VI, 174, 1895- 



4. BANKS, NATHAN. Note on Ccria Willis tonii Kahl, Proc. Ent. Soc. 



Wash. v. 310. 1903. 



4b. BARBER, H. S. Notes on a wood-boring Syrphid, Proc. Ent. Soc. 

 Wash. XV, 4, pp. 151, 2, 1913. 



5. BLOOMFIELD, E. N. Ento., Month. Mag. XXXIV, 244. 



6. BorcHE.. Stett. Ent. Zeit. p. 145. 1847. 



7. BRAUER, FRIEDRICH. Die Zweiflugler des Kaiserlichen Museums zu 



Wein TIL In Band XLVII. 1883. 



8. BUCKTOX, G. B. A Natural History of Eristalis tcna.v, the Drone- 



fly (London) 1895. 



9. CHAGXOX, E. Preliminaires sur ies Syrphides de la Province cle 



Quebec, 1901. 



' 10. COMSTOCK, J. H. A Manual for the Study of Insects. 

 IT. COQUILLETT, D. W. Notes on the Syrphid Fly, Pipiza radicum 



Walsh and Riley. Proc. Ent. Soc. Wash. Vol. VI, No. 4, p. 200, 



1004. 

 T2. DAECKE, V. A. E. Note on rearing of Xylota pigra Fabr.. Ent. 



News, XIV, 275, 1903. 



