ART. 20. NEW GENERA OF LEPTOGASTRINAE—ALDRICH. 5 
PSILONYX, new genus. 
Differs from Leptogaster only in the complete absence of empodia. 
Genotype.—Leptogaster annulatus Say. 
PSILONYX ANNULATUS Say. 
Leptogaster annulatus Say, Journ. Acad. of Nat. Sci., vol. 3, p. 75, 1823; Complete 
Works, vol. 2, p. 68.—Back, Trans. Amer. Ent. Soc., vol. 35, p. 159, 1909. 
In making this species the type of a new genus I am carrying out, 
after the lapse of a century, a suggestion made by Say in his original 
publication, as follows: 
The nervures of the wings of this insect, do not perfectly correspond with those of 
L. tipuloides, which circumstance, combined with another highly important difference 
that this insect exhibits, in having but two nails to the tarsi, would justify the generic 
separation of the annulatus from the tipuloides, and its reference to a distinct genus. 
Specimens in the writer’s collection from Ecuador do not seem to be 
distinct from others collected at Lafayette, Indiana. There are, 
however, some additional tropical species which can not at present 
be elucidated; and Mr. Back has described a second species from the 
United States, P. schaefferi from Brownsville, Texas. 
Genus LEPTOGASTER Meigen. 
Leptogaster Mr1GEn, Illiger’s Magazin, vol. 2, p. 269, 1803; Systematische Beschreib., 
vol. 2, p. 258, 1820. 
Gonypes LATREILLE, Histoire nat. Crust. et Ins., vol. 14, p. 309, 1804. 
Leptogaster Bacx, Trans. Amer. Ent. Soc., vol. 35, p. 155, 1909. 
Tipulogaster CocKERELL, The Entomologist, vol. 46, p. 213, 1913. 
In the original description Meigen mentioned only Asilus tipulordes 
Fabricius, which is now regarded as a synonym of Asilus cylindricus 
DeGeer. The type of Gonypes is also tipuloides. The type of 
Tipulogaster is badius Loew. 
There are many species of this genus, which appears to be wide- 
spread in the Eastern and Western Hemispheres, both in tropical 
and temperate regions. 
Genus CAENAROLIA Thomson. 
Caenarolia THomson, Kongliga Svenska Fregatten Hugenies Resa Omkring Jorden, 
vol. 2, Zoology No. 1, p. 470, 1868. 
Acronyches WitListon, Manual of North American Diptera, ed. 3, p. 388, 1908. 
Thomson described this genus from a single new species which 
he called longipennis. It was from Rio Janeiro. He refers to miles 
Wiedemann as belonging to the same genus, but gives no description 
of it... Wiedemann’s description of miles is so brief that it is evident 
that Thomson must have seen the type or he could not have assigned 
1 Dasypogon miles Wiedemann, Aussereuropiiische Zweifliigelige Insekten, vol. 1, p. 393, 1828, from 
Brazil. 
