No. 64] DIPTERA OF CONNECTICUT : TAXONOMY 367 



3. Thoracic pleura clear yellow, unmarked americanus 



Thoracic pleura yellow, with two narrow brown longitudinal stripes that 

 are best delimited in front pleural is 



Oxydiscus americanus (Alex.) (Fig. 43, A). 



li)l'2. Adelphomi/m americana Alexander; Pomona Coll. Journ. Ent., 

 4:829-831. 



Figs. — Alexander, Ibid., fig. 260, A (ven.). Alexander, Ent. News, 22:353, 

 fig. 4 (wing, as senilis); 1911. Alexander, Cfls. N. Y., 1, pi. 41, fig. 160 (ven.); 

 1919. 



Vein R2 present (Fig. 43, A). $. L. about 3-3.5 mm.; av. 4.2-4.6 

 mm. $ , L. about 4 mm. ; w. 5-5.5 mm. 



(Aug., Sept.) N. B., Me., N. H., Vt., Mass., N. Y., westw. to Mich., southw. to 

 N. C. and S. C. 



Connecticut.— Norfolk. June 6-12. 1928 (C. P. A., G. C. C.) ; Salisbury, Sept. 5-12. 

 1928 (C. P. A., G. C. C); Twin Lakes, Sept. 12, 1928 (C.P. A.): W. Granbv, Sept. 



11. 1928 (C.P. A.). 



O. cayuga (Alex.) (Fig. 43, B). 



1912. Adelphom,yia cayuga Alexander; Pomona Coll. Journ. Ent., 



4:831. 

 1916. Ormosia ahnormis Dietz; Trans. Amer. Ent. Soc, 42: 137-138. 

 1921. Adel/phomyia hazletoneihsis Dietz ; Ihid., 47 : 252-253. 



Figs.— Alexander, Ibid., fig. 260, B (wing). Alexander, Cfls. N. Y., 1, pi. 41. 

 fig. 162 (ven.) ; 1919. Dietz, Trans. Amer. Ent. Soc, 42, pi. 10, fig. 3 (hyp.) ; 1916. 



General coloration brown to dark brown, the pleura darkened, 

 somewhat paler behind. Vein R-2 usually faint and indistinct; macro- 

 trichia of cells relatively numerous l)evond level of outer end of cell 

 1st Mo ( Fig. 43, B ) . 5 .' L. 3-3.5 mm. : w. 4-5 mm. 9 . L. 4.5-5 mm. ; 

 w. 4.5-5 mm. 



(Aug., Sept.) Me.. N. H., Vt., Mass., N. Y., Pa., westw. to Ind. and Mich. 



O. minutus (Alex.) 



1911. Adelphomyia mmuta Alexander; Can. Ent., 43:287-288. 



Figs.— Alexander. Cfls. N. Y., 1, pi. 41, fig. 161 (ven.) ; 1919. Crampton, Insec. 

 Inscit. Menst., 13, pi. 3, fig. 24 (thorax) ; 1925. 



Wings with vein A% distinct. $. L, about 3.3-4.4 mm.; w. 4-4.2 

 mm. 9 . L. 4.5-5 mm. ; w. 4.5-4.8 mm. 



(Late May, June) Ont.. Que., N. B., Me., N. H., Vt., Mass., N. Y., Pa., westw. to 

 Mich., southw. to N. C . 



Connecticut.— Cornwall Bridge, Mav 30, 1931 (C.P. A.): Hartland, June 9, 1929 

 (C.P. A.); Kent Falls. Mav 30-31, 1931 (C.P. A.): Norfolk, May 30, 1931, June 



12, 1931, June 9, 1929 (C.P. A.); Union. June 14. 1933 (C.P. A.). 



O. pleuralis (Dtz.) 



1921. Adelphomi/ia pleural^ Dietz : Trans. Amer. P^nt. Soc, 47 : 251- 

 252. 

 Antennae brown, the pedicel dark brown. Abdomen light brown, 

 the subterminal seirnients dark brown, i . L. about 2.5-2.8 mm. ; 

 w. 3.3-3.6 mm. 9 . ^ L. 3.3-3.8 mm. ; w. 3.8-4.2 mm. 



