360 CONNECTICUT GEOL. AND NAT. HIST. SURVEY [ BuU. 



D. {PIect?'0772yia) modesia (O. S.) (Figs. 40, H: 42, C). 

 186i>. Plectromyia modcsta Osten Sacken; Mon. Dipt. X. Amer., 

 4:284. " 



l.'igs.— Osten Sacken, Ibid., 4. pi. 2, fig. 18 (wing). Williston, Man. N. Amer. 

 Dipt., Ed. 3:84, fig. 3 (wing); 1908. Alexander, Cfls. N. Y., 1, pi. 41, fig. 174 

 (ven.) ; 1919. 



(leneral coloration pale brown, with tliree slifjlitly darker brown 

 praeseutal stripes. Antennae dark throughout. Knobs of halteres 

 weakly infuscated. Wings nearly hyaline; stigma scarcely indicated; 

 veins pale l)rown. Abdomen brown, the hypopygium a trifle more 

 yellowish. Male hypopygium (Fig. 42, C). $ . L. 4.2-5 mm.; w. 5.5- 

 6 mm. $. L. about 5 mm.; w. 5-5.5 mm. 



(Tune) N. H., \i., in mountains. (High Canadian, Hudsonian). 



D. [Plecf I'omiihi ) ipei\o\2iia {XXex.) (Fig. 42, D). 



r.lli). Tricyphovd. petiolata Alexander; ('an. Ent., 51:194-195. 



(Jul\-, Aug.) Que., X. H. (Mt. Washington, 5000 feet and over), westw. to high 

 mountains of Colo. (Hudsonian). 



Subgenus Rhaphidolabis Osten Sacken 



Ls(i9. Rhapli/dolah'is Osten Sacken; Mon. Dipt. N. Amer., 4:284-287. 



A numerous group of small pediciine crane-flies that are most 

 commonly found along streams and in boggy wooded areas. The 

 early stages live in saturated earth. The adults are on the wing in 

 Spring and P'all, and some, at least, have two generations per year. 



Key to Species 

 (Based chiefly on male characters) 



1. Cell R^i of wings sessile or nearly so (Fig. 40, I) ; male hypopygium with the 



median region of tergite not or scarcely produced (in rogersiana. produced 



into a broad lobe with truncated apex) 2 



Cell R.i of wings long-petiolate (Fig. 40, J) ; male hypopygium with the 

 tergite produced medially into a slender lobe 4 



2. Male hypopygium with median region of tergite merely rounded, the lateral 



arms appearing as paddle-like blades, with rounded tips ; interbase short, 



bidentate at apex ; wings subhyaline to pale grayish 3 



Male hypopygium with median region of tergite produced into a broad 

 lobe, its apex truncate, the lateral arms small, each bent at apex into a 

 simple point ; interbase a long, nearly straight yellow rod, its apex micro- 

 scopically toothed (Fig. 42, I) ; wings milky-white rogersiana 



3. Coloration of thorax grayish brown, the praescutum with three dark brown 



stripes ; abdomen dark brown, the caudal margins of segments paler ; wings 

 very pale brown, Rs short, arcuated to angulated ; male hypopygium with 



interbase relatively narrow (Fig. 42, F) cayuga 



Coloration of thorax reddish brown, sparsely gray, pruinose, the praescutum 

 with three indistinct darker stripes ; abdomen yellowish brown, the hypo- 

 pygium bright yellow ; wings nearly hyaline, Rs somewhat elongated and 

 gently arcuate; male hypopygium with the interbase broader (Fig. 42, J) 



rubescens 



4. Thoracic pleura chiefly gray pruinose ; male hypopygium with the basistyle 



bearing a conspicuous darkened hairy lobe on mesa! face near base ; inner 

 dististyle somewhat bottle-shaped, broad basally, the outer half suddenly 

 narrowed into a neck-like portion, the apex obtusely rounded (Fig. 42, H) 5 



