THE CRANE-FLIES OF NEW YORK PART II 923 



a pentagon of five lobes, these being unarmed (0. innocens, 0. meigenii) or spinous-tipped 

 (0. nubila, 0. nigripila). 



Ormosia is a large and rather difficult genus (including more than 

 seventy-five species) of small crane-flies whrch are characteristic of sub- 

 arctic and temperate regions and apparently rare or lacking in the Tropics. 



The adult flies occur in small dancing swarms, usually in cool, shaded 

 situations in or near woods or along brooks. They are most numerous 

 in early spring and in late summer or early autumn, many of the species 

 being apparently double-brooded. 



The immature stages are spent in moist organic mud near water. In 

 Europe, Beling records Ormosia haemorrhoidalis (Zett.) (Beling, 1879: 

 48-49, and 1886:191-192), 0. lineata (Meig.) (Beling, 1886:202), and 

 0. nodulosa (Macq.) (Beling, 1886:202), as being found in wet earth in 

 woods, usually beneath leaf mold. Cameron (1917 : 65) likewise records the 

 last-named species as living in mud. 0. varia (Meig.) was found by De 

 Meijere (1916:201-204) among decaying leaves in a wet spot near a ditch. 



Of the American species, the writer has bred Ormosia innocens, 0. 

 nubila, 0. meigenii, and 0. nigripila from larvae or pupae in entirely 

 similar situations to those given above for the European species. 



Tho larvae of only two of these species, 0. nubila and 0. meigenii, are 

 available to the writer at this time. 0. nubila is a large brown species; 



0. meigenii is much slenderer, and is light yellow in color. 



The pupae of the known Nearctic species may be distinguished as 

 follows: 



1. Dorsum of eighth abdominal segment with a pentagon of five lobes which are spinous 



at their tips 2 



Dorsum of eighth abdominal segment with a pentagon of five fleshy lobes 3 



2. Crest of mesonotum with a flattened chitinized plate on either side of median line. 



0. nubila (0. S.) (p. 923) 



Crest of mesonotum tumid, with abundant coarse, yellowish setae on either side of median 

 line 0. nigripila (0. S.) (p. 927) 



3. Abdomen with large, rectangular, dusky areas on posterior annuli of segments 2 to 8, 



giving abdomen a banded appearance; pleural setae rather numerous. 



0. innocens (O. S.) (p. 925) 

 Abdomen without such dusky areas: pleural setae few in number. 



0. meigenii (O. S.) (p. 928) 



Ormosia nubila (0. S.) 



1859 Erioptera nubila O. S. Proc. Acad. Nat. Sci. Phila., p. 227. 



Ormosia nubila is probably double-brooded, since the flies are on the 

 wing in the spring and again in the fall. The immature stages live in 



