New Genera and Species of PsilopincX. 



BY J. M. ALDRICH. 



The genus Fsi/opi/s has heretofore occupied a place apart iu the 

 family Dolichopodidae. Notwithstanding the immense number of 

 species, comprising some ninety in America alone (if we may trust 

 the descriptions), no acceptable plan of dividing the genus has yet 

 bean propose.!. Bigot's attempt (Ann. S:3C. Ent. Fr., Oct., 1890, p. 

 268) is the latest. His high estimate of the value of the antennal 

 modifications has led him to overlook other characters, and select, 

 in two instance, a nodule or disk on the arista of the male antenna 

 as the basis of a new genus. This is too slight a character for the 

 purpose. The apical or dorsal insertion of the arista, which he uses 

 to separate two groups of genera, would, if well-marked, be important; 

 but when it is necessary to explain at some length just how far up 

 from the apex the arista may be and yet be " apical or subapical, " 

 the value of the distinction sinks into insigniticance. 



Loew (Mon. N. A. Dipt. II, 231) suggested that the color of the 

 tegular cilia seemed to offer the best ground for division of the genus. 

 In the line of his proposition, I have found that these cilia, when 

 black, are associated with four large bristles on the scutellum, and a 

 third longitudinal vein of the wing which curves backward at the tip 

 in the normal manner. When they are pale, the scutellum has only 

 two large and usually two small bristles, and the third vein near its 

 tip is distinctly curved forward. ])arallel or nearly so with the branch 

 of the fourth vein. Thus we find ample ground in three distinct 

 characters, applicable to both sexes, for the division of the genus. In 

 an examination of about thirty species, these characters apply per- 

 fectly to all but one: in this, a South American species, the curved 

 vein is associated with four large scutellar bristles and the tegular cilia 

 are half pale and half black. This species I would include among 

 those with black cilia. 



Adding to these two genera two more which are new to science, 

 described in this paper, we ha\'e the section Psilopinae of the family 

 Dolichopodidae thus characterized: 



Fourth longitudinal vein with a widely divergent fork on the front 

 side: or if not, then the head wider than the thorax, face wide, and 

 the front deeply excavated. 



(47) KAN. UNIV. qUAR, VOr,. II. NO. 1, JULY, 1893, 



