1914.] NATIRAL SlIKM KS OK I'lIlLAOHLPlllA. o93 



light l)ro\vn, rather darker medially; seutelluin more yellow me- 

 dially; postuotum gray. Pleurse dull light yellow with a hroad dark 

 brown stripe e.\t ending from the cervieal .selerites to the poslnotum; 

 mesosternmn suffused with brown. Haheres light yellow, the 

 knobs darker. Legs, coxa and trochanters dull yellow, femora 

 brownish yellow, tibiie similar, the tip narrowly brown, tarsi brown. 

 Wings subhyaline, stigma indistinct, veins brown; venation (PI. 

 XXV, fig. 3). 



Abdominal tergites dark brown, sternites murh paler, yellowish 

 white, hypopygium brown. 



Holotypc, cf, Sacandaga Park, Fulton Co., N. Y., June 20. 1910. 



Allotype, 9 , topotypic. 



Paratypes, 50 cT 9 , topotypic; Mountain Lake, Fulton Co.. N. Y., 

 alt. 1,580 feet, June 15, 1914; Orono, Penobscot Co., Me., July 29, 

 1913; Ithaca, Tompkias Co., X. Y., July 7, 1911; Kidgewood, 

 Bergen Co., X. J. 



A common and widely distributed species in the Eastern United 

 States; the material has been compared with the types of conlempta 

 in the Museum of Comparative Zoolog\% and the form differs as 

 described above. The species has been in the collection of Mr. 

 Leonard and myself for some years. 



A key to the species of the luteipennis group-in the Eastern United 

 States. 



1. Cell Ml absent novcbomccmis .\lex.^ 



Cell .¥, present 2. 



2. Wings with small brown dots on the cross-veins and at the forks, 



hiteipennis O. S.' 

 Wings clear, unspotted 3. 



3. Thorax clear blue-gray inornala O. S.' 



Thorax brownish without gray color -1. 



4. Larger species with the pleurae unmarked rnnlenipta i}.r<.'^ 

 Smaller species; [jleunc with a conspicuous dark brown stripe 



from the cervical selerites to the.postnotum, 



nigripleura A. & L., sp. n. 



The mcml.)ers of the luteipennis group have the following charaeters 

 in common: head narrow and prolonged behind; pronounced 

 pseudosutural or humeral pits; conspicuous tuberculate pits on 

 either side of the middle line of the prascutum in front. Venation 



* noveboracensis Alexander; Pysche, vol. 18, pp. 196 to 198; 1911. 

 *luteipennis Osten Sacken; Proc. Acad. Nat. Sci. Phila., p. 236; 1859. 

 Unornata O.sten Sacken; Mon. Dipt. X. Am., vol. 4, pp. 219, 220; 1869. 

 »con/empta Osten Sacken; i.e., pp. 218, 219; 1869. 



