44 NEW YORK STATE MUSEUM 



distinct middorsal row of minute brown longitudinal dashes. 

 Appendages all brown, the inner ones angulated and thickened 

 in the middle and bent upward thereafter to the tip (this appear- 

 ing only in lateral view; hence not shown in the figure) ; forceps 

 (pi. 10, fig.lO) strongly directed downward, the basal segment 

 distinctly differentiated, the apical segment unusually long and 

 slender. 



The female imago is greenish yellow, with pale whitish legs and 

 setae. The basal segments of the antennae are brown and there 

 is a pale brownish tinge to the dorsum of the thorax and the 

 lateral margins of the abdomen. Wings hj^aline, veins whitish. 

 The ventral apical lobe of the 9th abdominal segment surpasses 

 the tip of the 10th segment and is obtusely rounded apically. 



The male subimago is dark greenish brown, darker on the head, 

 the top of the thorax and the apex of the abdomen; the abdominal 

 sutures, however, are distinctly paler. I^gs pale yellowish or 

 greenish, the fore tarsus pale brownish. Wings smoky brown. 

 The two dorsal apines are paler in 'the J^ subimago and absent 

 in the ?. 



The nymph. Length, 9 mm; seta, 4.5 mm, additional. Body 

 elongated rather slender, depressed, thinly hairy, widest across 

 the mesothorax. Head short ; face oblique. Antennae hardly 

 longer than the head, almost bare. Labrum quadrangular, one 

 fourth wider than long, emarginate' in front and hairy on the front 

 border, the hairs being longest on the outer angles. Mandibles 

 short and thick, with the outer canine very broad, 3-toothed at 

 apex, the inner canine of equal length but slenderer; molar sur- 

 face narrow. Maxillary palpus hardly half as long as the lacinia. 

 Third joint of the labial palpus a conic rudiment. 



Thorax fiat below, well rounded above; legs short and thinly 

 hairy; claws (pi. 10, fig.5) with inferior row of about 10 denticles. 



Abdomen depressed, its lateral margins serrate by reason of the 

 flat lateral spines in which the side margins of segments 3-9 ter- 

 minate. There are two rows of dorsal spines on segments 3-8, 

 erect laiterally, flattened, almost cultriform. Gill lamellae present 

 on segments 3-7, double; anterior lamina thickened, covering the 

 delicate posterior one, trapezoidal, obtusely pointed at its inner 

 apical angle, palmately veined ; posterior lamina shorter, thinner, 

 its margins cut into a small number of fingerlike filaments. The 

 lamellae regularly overlap, each anterior lamina covering the 

 basal fifth of the one behind it, that of segment 7 shorter. Setae 

 closely parallel, slender, fragile, sparingly pilose. Their two 

 proximal articulations faintly ringed with brown. Color 

 olivaceous, with a broad l>and of brown extending from the rear 

 of the eye to tlie base of the lateral caudal seta. There is also a 

 narrow middorsal line of brown on the abdomen. 



