328 D1PTERA OF NORTH AMERICA. [PART II. 



black little hairs almost upon the whole front side. Feet yellow. 

 The hind femora before the tip with a bristle, upon the greater 

 part of the under side sparsely ciliated with rather long yellowish 

 hairs. Hind • tibia; of ordinary strength, not infuscated at the 

 tip, Avith a long glabrous streak upon the hind side. Fore tarsi 

 abundantly one and a half the length of the tibia? ; the first four 

 joints yellow, on the inside with a somewdiat whitish reflection ; 

 stalk-shaped from the first to the third joint ; the fourth joint late- 

 rally compressed, somewhat broader than the preceding, especially 

 towards the tip ; the first joint nearly as long as the three follow- 

 ing together; the fifth joint black, compressed, broad, especially 

 towards the tip, beset on the upper side with closely appressed 

 little hairs. Middle tarsi blackened from the tip of the first joint. 

 Hind tarsi altogether black. Cilia of the tegula? whitish. Wings 

 hyaline, somewhat grayish, of rather uniform breadth ; the costa 

 at the tip of the first longitudinal vein with a weak and very 

 short swelling ; the fourth longitudinal vein not broken. 



Hab. White Mountains, New Hampshire, July, 1863. (Osten- 

 Sacken.) 



Observation. — This species has an extraordinary resemblance 

 with D. splendidus on one side, and with D. subciliatus on the 

 other. It differs from D. splendidus, with which it agrees more 

 with regard to the structure of the fore tarsi, by the less densely 

 ciliated hind femora, and by the smaller extent of the incrassa- 

 tion of the costa. D. subciliatus has longer and more slender 

 fore tarsi, the fourth joint of which is as slender as the preceding ; 

 it has the hind tibia? infuscated at the tip ; the cilia of its hind 

 femora are not only more scarce but also shorter, finally the swell- 

 ing of the costa is more extended. Moreover, not only D. splendi- 

 dus, but also D. subciliatus are considerably larger than D. splen- 

 didulus. This character will enable us to distinguish the female 

 of D. splendidulus from that of D. splendidus, as well as from 

 the female of D. subciliatus ; the two latter, however, cannot be 

 confounded on account of the different color of the hind tibia?. 



45. D. palaestricus Loew. % and $>• — JEneo-viridis,pedibus flavis, 

 coxis anticis tibiisque posticis totis concoloribus, antennis tarsisque 

 posticis nigris, ciliis oculorum inferioribus tegularumque ciliis flavi- 

 cantibus, vena alarum longitudinali quarta non fractal 



^ . Ultimo tarsorum anticorum articulo admodum dilatato, nigro, in latere 



