No. 64] DIPTERA OF COXXECTICUT : TAXONOMY 361 



Thoracic pleura chiefly yellow, the ventral steriiopleurite dark ; male hypo- 

 pygium without a lobe on mesal face of basistyle; inner dististyle elongate, 

 more blade-like, gradually narrowed to a subacute tip (Fig. 42, K) 6 



5. Male hypopygium with intcrbase a flattened blade that terminates in two 



slender arms directed toward one another, to appear more or less like tongs ; 

 lateral arms of tergite appearing as a long, slender, strongly curved hook 



(Fig. 42, G) ■ forceps 



Male h.\popygium with interbase bearing two unequal arms, one a Ijroadly 

 flattened blade, the shorter arm slender, sinuous ; lateral arm of tergite 

 only gently curved at apex (Fig. 42, H) persimilis 



6. lilale hypopygium with interbase terminating in a slender spinous point, tlie 



structure somewhat resembling the head and beak of a bird ; lateral arm of 

 tergite only slightlv curved at apex; apex of inner dististvle subacute (Fig. 



42, E) . .' '. ' !.avis 



Male hypopygium with interbase a broadly flattened blade, tlie apex nar- 

 rowed and obtusely rounded ; lateral arm of tergite very strongly recurved 

 into a hook; apex of inner dististyle more obtuse (Fig. 42. K) tenuipes 



Dicranota {RhapMdola'bu) avis (Alex.) (Fio-. 4'2. E). 

 lO'iC. Rhaphidohihis {Rhaphidolahis) oris Alexander: \\u{. News, 

 37: 50, 51. 



Closely allied to tenuipes, differin<i- chiefly in the structure of the 

 hypopygium, notably of the interbase (Fig. 42, E). Praescntal stripes 

 broad. $ . L. 5.5-5.8 mm. ; w. 5.8-6.3 mm. 



(Aug., Sept.) Mass. and Ct., southw. to Va. and N. C. 



Connecticut.— Cornwall Bridge, Aug. 19, 1931 (C. P. A); Kent Falls, Aug. 19, 

 1931 (C P. A.). 



D. (Rhophidolabis) cayuga, (Alex.) (Figs. 40,1; 42, F). 

 1916. Rhaphidolabis {RhapTiidolahh) cayuga Alexandei-; Proc. 

 Acad. Nat. Sci. Philadelphia, 1916 : 543-544. 



Figs.— Needham, 23rd Kept. N. Y. St. Ent. for 1907, pi. 13, fig. 1 (wing): 

 1908 (as tenui;)cs). Alexander, Proc. Acad. Nat. Sci. Philadelphia, 1916, pi. 2R, 

 fig. 57 (wing) ; 1916. Alexander, Cfls. N. Y., 1, pi. 41, fig. 173 (wmg) ; 1919. 



Antennae dark brown. Head brownish gray. Knobs of halteres 

 dark brown. Wings (Fig. 40,1) with stigma pale brown: cell Rz 

 shortly to broadly sessile. Male hvpopygium (Fig. 42. F) brownish 

 yellow. $ . L. 5-5.5 mm. ; w. 5.5-(3.5 mm. ? . L. 6.5-7 mm. ; w. 7.5 

 mm. 



(May, June; Aug., Sept.) Que., Me., N. H., N. Y., Pa., westw. to Mich., southw. 

 to S. C. 



Connecticut.— Norfolk, May 16, 1931, Sept. 12, 1928 (C. P. A.); Twin Lakes, Sept. 

 12, 1928 (C. P. A.). 



D. (Rhaphidolahis) forceps (Xlex.) (Fig. 42, G). 

 1924. Rhaphidolahis (Rhaphidolahis) forceps Alexander: Bull. 

 Brooklyn Ent. Soc, 19 : 63, 64. 



General coloration of thorax gray, the praescutum with three dark 

 brown stripes. Antennae black throughout. Wings with a faint bi-own 

 tinge, the stigma darker; Rs weakly angulated to strongly arcuated: 

 basal section of ^5 very short to lacking. Abdomen dark brown. 

 Male hypopvgium (Fig. 42, G) much as in persimilis. ditt'ering es- 



