DIPTERA— ORTALID J;}. 54 1 



for some distance and then suddenly curves, almost bends upward. In 

 Lithortalis the separation is gradual and not abrupt. In Ceroxys the small 

 transverse vein lies below or outside the tip of the first longitudinal vein ; 

 in Lithortalis it lies within it. In the pattern of the markings also it differs 

 from Ceroxys in that there are no spots whatever before the larger trans- 

 verse vein, excepting that the stigma, or the space lying between the auxil- 

 iary and first longitudinal veins, is testaceous. 



Lithortalis picta. 



PL 3, Figs. 10, 1(>. 



Lilliortalis picta Scudd., Rep. Progr. Geol. Surv. Can., 1875-1876, 277 (1877). 



The thorax, part of the abdomen, and both wings of the single specimen 

 preserved show the upper surface of the body with expanded wings. The 

 abdomen is without markings. The wings are very well preserved, the 

 apex slightly angulated between the third and fourth longitudinal veins ; 

 the costa nearly straight on its basal half, strongly convex beyond ; the 

 stigma occupies the entire space between the auxiliary and first longitudinal 

 veins and is dark castaneous, deepening toward the costa to blackish fus- 

 cous ; the costal vein is blackish fuscous ; the other veins are luteo-testa- 

 ceous, deepening to blackish fuliginous next or in the spots ; the other spots 

 are dark fuliginous, deepening toward the veins or the margin, and consist 

 of a narrow belt following the larger transverse vein and of confluent spots 

 at the tips of the second, tliird, and fourth longitudinal veins, forming a nar- 

 row marginal belt from just below the tip of the fourth longitudinal vein 

 to half-way between the tips of the first and third longitudinal veins, broad- 

 ening slightly at the extremities of the veins in rapidly narrowing shoots, 

 which follow the veins a short distance. 



Length of thorax and fragment of abdomen, 3""" ; breadth of thorax, 

 1.25°"°; breadth of abdomen, LS™""; length of wing, 5°"" ; breadth of same, 

 1.75°"°. 



Quesnel, British Columbia. One specimen, No. 5 (Dr. G. M. Dawson, 

 Geological Survey of Canada). 



