The Crane-Flies of New York — Part 1 925 



Genus Dicranota Zetterstcdt 

 1838 Dicranota Zett. Ins. Lapponica, Dipt., p. 851. 



In the genus Dicranota there are about fifteen known species, restricted 

 to the northern Holarctic region. The species are readily distinguished 

 from those of llhaphidolabis by the supernumerar}'- cross-vein in cell Ri 

 of the wings. The larvae are carnivorous, feeding largely on Tubifex 

 worms (Miall, 1893). The local species of Dicranota may be separated 

 according to the following key, which is adapted from a key to the 

 North American species already published by the author (Alexander, 

 1914 b: 601). 



1. Cell M, absent 2 



Cell Ml present 3 



2. Halteres with the knobs darkened; antennae of male much longer than the thorax. [Mon. 



Dipt. N. Amer., part 4, p. 281-282. 1869.] D. eucera O. S. 



Halteres pale; antennae of male short. [Proc. Acad. Nat. Sci. Phila., p. 249. 1859.] 

 (Plate XLI, 169.) D. rivularis 0. S. 



3. Cell Ut Ml present; color of body yellowish. [Proc. Acad. Nat. Sci. Phila., p. 599-600, 



pi. 27, fig. 31. 1914.] (Plate XLI, 167.) D. pallida Alex. 



Cell 1st M: absent; color of body gray. [Proc. Acad. Nat. Sci. Phila., p. 600. 1914.] 

 (Plate XLI, 168.) D. noveboracensis Alex. 



Genus Rhaphidolabis Osten Sacken 



1869 Rhaphidolabis 0. S. Mon. Dipt. N. Amer., part 4, p. 2M. 

 1869 Plcdromijia O. S. Mon. Dipt. N. Amer., part 4, p. 282. 



The genus Rhaphidolabis includes about fourteen described species 

 found in the Holarctic region and in the mountainous sections of the 

 Oriental region. The larvae are carnivorous, and live in rich organic 

 mud or in the streams near by. Needham (1908:212-214) has given 

 a description of the larva of the species R. tenuipes. The following key, 

 adapted from a key to the North American species of Rhaphidolabis 

 already published by the author (Alexander, 1916:541-542), divides the 

 local species of the genus: 



1. Antennae 15-segmented; cross-vein m present. (Subgenus Rhaphidolahina Alex.) [IVTon. 



Dipt. N. Amer., part 4, p. 288. 1869.] (Plate XLI, 170.) R. flaveola O. S. 



Antennae 13-segmented; cross-vein m absent 2 



2. Cell Ml absent. (Subgenus Plectromyia O. S.) [Plectromyia modesta O. S. Mon. Dipt. 



N. Amer., p. 284. 1869.] (Plate XLI, 174.) R. modesta (O. S.) 



Cell Ml present. (Subgenus Rhaphidolabis 0. S.) 3 



3. Cell R2 petiolate. [Mon. Dipt. N. Amer., p. 287. 1869.] (Plate XLI, 171.) 



R. tenuipes O. S. 

 Cell Ri sessile 4 



