No. 3-] HYGROCELEUTHUS AND DOLICHOPUS. 1 35 



except a large black blotch on inner side ; lamellae of hypopy- 

 gium fringed with comparatively short hairs. 



Marginatns. Face gray ; all the legs plain ; front tarsi grad- 

 ually darker toward tip ; hind tibiae more infuscated at apex ; 

 lamellae fringed with numerous longer hairs. 



The females of these species cannot be separated. They 

 agree rather with margijiatits in the color of the postocular 

 cilia and of the legs. The males, evidently so distinct, were 

 taken, together with the females, in the same netful at Woods 

 Holl, Mass., by Dr. Wheeler. Marginatzis is the commoner 

 form. In all were taken from July 14 to August 9, 1899, 

 forty-eight females, thirteen male Henshawi, and nineteen 

 male niarghiatus. 



Dolichopus partitus, sp. nov. 



Femora chiefly black, cilia of inferior orbit black, wings infuscated, coxae 

 wholly black. 



Male. Length 5-5.5 mm., of wing the same. Dark green with metal- 

 lic lustre. Proboscis and palpi black. Face rather wide, short, con- 

 cave beneath the antenna, and with a pronounced transverse ridge at its 

 lower fourth, below this convex. Face covered with light brown pollen, 

 except a small spot at each side of the ridge. Antennae totally black ; the 

 first joint with short bristles above ; the bristles about the apex of the sec- 

 ond joint much longer below. Third joint short, ovate, obtusely pointed at 

 tip ; arista black, pubescent. Front 

 dark violaceous green. Postocular 

 cilia totally black. Thorax above, 

 dark green, with a median longitudi- 

 nal dark cupreous band. Scutellum 

 of same color as thorax. Abdomen 

 metallic green, lighter than thorax. Fig. 12.-/). Azr^//«.: male wing. 



Surface covered with short black 



hairs, more sparse towards base ; very slightly covered with whitish dust. 

 Hypopygium almost black, shining with two patches of black hair on dorsal 

 side near the base ; internal appendages ferruginous. Lamellae yellow, of 

 usual size, with a black border. Between the white center and black border 

 is a ferruginous band. The border is very much jagged at apex and furnished 

 with strong bristles, becoming more slender towards base. Pleurae greenish- 

 black, covered with whitish dust ; coxae black. Legs black, except femora 

 and tibiae just at their articulation, the four anterior tibiae and the base of 

 the first joint of four anterior tarsi. Posterior femora not ciliated. Wings 

 infuscated about cross-vein and at apex between costa and third vein. The 



