226 Journal New York Entomological Society. [VoL x. 



subniarginal lateral bands running backward from the lateral angles and paling 

 posteriorly ; a median transverse band connecting lateral bands and also a V-shaped 

 internal band with its upper ends uniting with the lateral bands near the anterior 

 angles. Metathorax longer than prothorax ; the suture between the meso- and 

 metathorax plainly visible both on the dorsal surface and at the lateral margins ; 

 posterior margin slightly angulated, with a fringe of short hairs ; whole segment 

 dusky with darker anterior and lateral, marginal bands; posterior angles with two 

 rather long hairs. 



Abdomen large, oval, slightly inclined to be clavate ; segments subequal, with 

 slightly projecting posterior angles having three hairs of different lengths, except in 

 the first and ninth segments, which have but two ; segments one to eight with heavy 

 lateral bands, slightly clearer at the sutures, and the posterior margins with a fringe 

 of short, unpustulated hairs ; ninth segment much narrower, quadrate, and with the 

 posterior portion clear and fringed with fine hairs; whole interior of abdomen evenly 

 dusky, not broken at the sutures. 



Legs long and slender, except the front femora, which are greatly dilated, being 

 almost orbicular ; first and second pairs of femora with several short hairs on the 

 anterior and posterior margins ; posterior femora with a sulnnarginal row of fine hairs 

 along the anterior side for nearly the entire length of the segment ; tibias with a few 

 short hairs along the margins and with dark, slightly broken, borders to the two 

 anterior pairs ; posterior tibiae very slender, parallel-sided, and without marginal 

 markings; first joint of tarsi short, second long and stout. 



The male is much smaller than the female ; head not quite so broad in front ; 

 abdomen oval ; the hairs of the posterior angles much shorter, except on the fourth, 

 seventh, eighth, and ninth segments, where they are extremely long; the posterior 

 femora are as long as in the female, and more swollen ; the posterior tibiae are twice 

 as long as the two anterior pairs, being as long as in the female, swollen apically and 

 heavily margined with deep brownish, slightly broken near the tip ; the genital hooks 

 are long and slender, reaching from the middle of the fifth segment to the tip of the 

 abdomen. 



The male measures: body, length 1. 96 mm., width .75 mm.; head, length 

 .45 mm., width .61 nmi. 



Four males and one female collected from two individuals of the 

 White-throated Swift {Aero/ia/ites i/wlafioleucus) at Warbonnet Canon, 

 Sioux Co., Neb., May 30, 1901. It resembles JV. pu/icaris, and 

 differs chiefly in the absence of the darker transverse, abdominal 

 bands and the pustules of the dorsal, abdominal hairs. 



Trinotun conspurcatum Nifzsch. (Plate XXI, Fig. 3.) 



This species resembles T. luriihim, but is easily distinguished by 

 the darker background, the larger size, the narrower, clear, transver.se 

 bands at the abdominal sutures, and especially by the fact that the 

 dorsal hairs of the abdomen arise from large clear pustules which is 

 not the case in luridiim. 



