December 1S93 ] 



PSYCHE. 



569 



THE DOLICHOPODID GENUS LIANCALUS LOEW. 



BV J. M. ALDRICH, MOSCOW, IDAHO. 



The genus Liancalus contained only 

 one known North American species at 

 the time of the publication of Loew's 

 monograph in 1S64; subsequently Osten 

 Sacken in his Western Diptera described 

 another. The present paper describes 

 two more. I have not seen either of the 

 earlier species, but it happens that one 

 of the following is a near relative of 

 Loew's, the other of Osten Sacken's, 

 species. 



Mik has separated a part of the 

 European members of the genus to form 

 the genus Alloeoneurus. None of the 

 known American species are included 

 in this new group. 



The females of the following species 

 have few it" any available separative 

 characters, except the yellow knees in 

 genitalis. 



Table of species. 



1. First joint of fore tarsi of male shortened. 



Second joint of fore tarsi of male short- 

 ened. 3- 



2. Last three joints of male fore tarsi of nearly 



equal length. similis, n. sp. 



Third joint as long as fourth and fifth 



together. querulus, O. S. 



3. Knees yellow. genitalis, Loew. 

 Knees not yellow. hydrofhdus. n. sp. 



Liancalus hydrophilus, n. sp. 



$. Front concave, green, somewhat over- 

 laid with whitish dust, especially about the 

 angles. Face rather wide, divided just below 

 the middle by a transverse elevation, which 



forms two slight arches toward the antennae. 

 Above this elevation the face is concave, shin- 

 ing green ; below it, flat and densely silvery- 

 white pollinose. The flat palpi are silvery 

 pollinose with a few black hairs. Antennae 

 wholly black, short, the third joint with a 

 blunt point. Cilia of the orbit black above, 

 white below. 



Thorax with a single median row of acros- 

 tichal bristles, smaller anteriorly; with two 

 reddish-bronze longitudinal lines (enclosing 

 a golden-green one;, abbreviated behind; on 

 each side of these median lines is an area of 

 beautiful blue color; beyond this, near the 

 border of the dorsum, another bronze line, 

 wide, semi-interrupted at the suture, an 

 attenuated portion reaching nearly to the 

 scutellum. The latter with six bristles. 

 Pleurae green, more or less overlaid with a 

 white dust, the metallic color usually show- 

 ing through but slightly. This covering of 

 white dust extends over the dorsum, except 

 upon the bronze portions. Cilia of tegulae, 

 whitish ; halteres yellow. 



Abdomen elongated, cylindrical, club- 

 shaped at the apex, from which two long 

 filaments project forward below, each bearing 

 two lateral rows of upward-curving, long 

 whitish hairs; these filaments almost reach 

 the hind coxae. Sides of abdomen with 

 sparse and delicate pile, longer on the 

 anterior segments, forming a distinct pos- 

 terior fringe on the first segment. General 

 color of abdomen bluish-green, with white 

 dust, except as follows: first segment with 

 narrow brown posterior border; second and 

 third segments with a narrow brownish-black 

 border in front and a wide one behind, some- 

 what coalescing dorsally in an indistinct line; 

 distal half of the fourth segment and a rather 

 wide dorsal stripe brownish-black; fifth seg- 



