224 THE CANADIAN ENTOMOLOGIST 



NEW NEARCTIC CRANE-FLIES (TIPULID^, DIPTERA). PART X. 



BY CHARLES P. ALEXANDER, 



State Laboratory of Natural History, Urbana, Illinois. 



Ormosia friscni, sp. n. 



Closest to 0. meigenii (O. S.) ; inner pleural appendage of the male hypopy- 

 gium with a conspicuous lateral spine; all four gonapophyses of approximately 

 equal size and shape. 



Male. — Length 3-3.5 mm.; wing 4-4.5 mm. 



Female.- — Length 3.8-4 mm.; wing 4-4.8 mm. 



Rostrum and palpi dark brown. Antennae brownish black; flagellai" seg- 

 ments oval, provided with a dense white pubescence and rather elongate verticils. 

 Head yellowish grey. 



Pronotum brown, the scutellum pale whitish yellow. Mesonotum uni- 

 formly brownish gray with a sparse yellowish bloom; pseudosutural foveae 

 conspicuously oval, black; tuberculate pits conspicuous, separated from one 

 another by a distance a little greater than the diameter of one. Pleura light 

 plumbeous. Hal teres whitish. Legs with the coxse plumbeous; trochanters 

 light brown ; femora brownish yellow, the tips broadly darkened ; tibiae and 

 tarsi dark brown. Wings with a strong brownish gray tinge; stigma darker 

 brown; conspicuous whitish areas before and beyond the stigma: basal cells 

 largely whitish; veins dark brown. Venation: cell 1st M^ open by the atrophy 

 of the outer deflection of Ms; anal veins convergent. 



Abdomen dark brown, including the hypopygium. Male hypopygium 

 with the inner pleural appendage smaller than the outer, before the tip with 

 an acute black spine set at a right angle to the appendage; outer appendage 

 strongly curved, the tip acute. Gonapophyses four in number, black, of approxi- 

 mately equal size and shape, the inner pair a little more slender than the outer 

 pair ; outer apophyses with a tiny tooth at about two-thirds the length on the 

 inner face; inner apophyses with the basal half flattened, the distal half strongly 

 narrowed; penis-guard slender, pale in colour. Ninth sternite with a spatulate 

 lobe as in the group. 



Habitat. — Illinois. 



Holotype.— d', Muncie, May 15, 1920, (Alexander). 



Alloto polype. — 9, (Prison). 



Paratopotypes.—l d', May 8, 1920, (Prison); 32 0^9*8, May 15, 1920, 

 (Alexander & Prison). 



Type in the collection of the Illinois State Natural History Surv^ey. 



Ormosia frisoni bears a considerable resemblance to 0. meigenii (O. S.) but 

 IS readily told by the smaller size, differently coloured wings and, especially, 

 by the structure of the male hypopygium. In 0. meigenii the inner pleural 

 appendage has the tip narrowed into a chitinized point that is in a straight 

 line with the axis of the appendage; of the four gonapophyses, the inner pair 

 are approximately one-half longer than the outer pair. This interesting new 

 species is dedicated to the collector, my friend, Mr. Theodore H. Prison, 



This species occured near the margin of a prairie cat-tail swamp where 

 it was associated with Psetidolimnophila liiteipennis (O. S.) and Tipula dejecta 



October, 1920 



