150 DOLICHOP1DJE. 



Genus I. PSILOPUS. 



PSILOPUS, Mg. zw. (1824); Mq.; Ztt. Leptopus, Fin. Sciapus, Zlr. 



Dolichopus p., LI.; Fb. s. a; Wd. z.m; Lhm. Musca^., Fb.; Gm. 

 Antenna articulo tertio patelliformi, ante apicem arista deflexa. Oculi 



glabri. Vena prabrachialis furcata, ramo anteriore oblique Jlexo prope 



cubitalem exeunte. Hypopygium marls extricatum, appendicibus tenuibus. 



Very slender. Eyes apparently glabrous, separated in both sexes ; 

 the lower orbit fringed with soft white hairs ; the face usually broad, 

 more so in the female. Third joint of the antennae short and rounded, the 

 slender pubescent arista placed on its upper edge ; the penultimate joint 

 short, but usually extending beyond the end of the third, and forming 

 an angle with the last, which is drooping and often very long. (In 

 P. platypterus the fourth joint is particularly short, and less distinct.) 

 Wings usually broad, with the anal angle rounded away : the prabra- 

 chial vein in its last or subapical tract forked, the posterior branch 

 running on straight, but becoming faint, and usually vanishing before 

 the margin, the anterior branch distinct (in P. platypterus faint), in- 

 clined forwards, with a strong flexure, and reaching the margin close to, 

 without however meeting, the cubital vein. The alula3 have a narrow 

 denticulated black edge and a radiating fringe of hairs. The abdomen 

 of the males is very long and slender, nearly cylindrical, and a little 

 arched, showing six segments above ; the hypopygium disengaged from 

 the ventral cavity, broad, compressed, with a number of slender ap- 

 pendages of various form and length. In the female the spines of the 

 vagina are longer than usual. The legs are very long and slender, the 

 spines of the tibiaa few and slight. In the females of all, the fore coxae, 

 and the lower edge of the fore femora in their first half, are pectinated 

 with a few long pale spines ; which are slighter in the males, if found 

 at all in this sex. 



The warmer climates of both hemispheres abound in the species 

 of this genus ; some of them, with variegated wings, among the 

 handsomest of the family. The few species that occur in the 

 British islands have the wings spotless, the first two joints of the 

 antennae and the greatest part of the legs pale yellowish. They 

 may be distributed as follows : 



a. First joint of hind tarsi twice as long as the second. Species 1. 

 a a. First joint of hind tarsi little longer than the second. 

 6. Abdomen with narrow indistinct bands only. 



c. Fore tarsi with peculiar marks in the male. Species 2, 3. 

 c c. Fore tarsi alike in both sexes. Species 4, 5. 

 b b. Abdomen with broad dark bands. Species 6. 



1. platypterus, Fb. s. a. 270. 20(1805); Mg.; Mq.; Zlr.; St. 

 ill. h. pi. 45. f . 4 ! tipularius, Fin. ; Ztt. Pallide aneo-viridis, capite 

 albido, pedibus pallidis, metatarsis omnibus elongatis ; Mas. alis divari- 

 catis, femoribus anticis sub apice crinitis, tarsis intermediis ante apicem 

 atrum albis. Long. 2-3 ; alar. 5 lin. 



