ZiH E. T. CRESSOiV. 



ticulated, the reticulations radiating from the prominent spine; posterior face of 

 metathorax divided into coarse reticulations by transverse ridges, median area 

 flat and finely reticulated. Twelfth joint of antennse thickest; thirteenth joint 

 almost equalling the scape in length, excavated beneath. Seventh segment of 

 abdomen terminating in an obtuse angle, its upper face having a sharp ridge on 

 each side, the ridges terminating in stout spines. 



" Easthainpton, Mass., July 2-l:th. The form of the apex of the ab- 

 domen will at once distinguish this from the species which it resembles." 

 Not identified. This may prove to be identical with aurinotus Say." 



Nysson compactus n. sp. — 9 .—Short, broad, robust, black, opaque ; head 

 and thorax coarsely, somewhat confluently punctured, clothed with a very short, 

 subappressed, pale pubescence, that on vertex and thorax above yellowish, that 

 on face, clypeus and sides of metathorax more dense and silvery ; space between 

 ocelli not raised; two spots on posterior margin of prothorax, sometimes a dot on 

 tubercles, spot on basal middle of scutellum, generally a short line on apex of 

 anterior femora beneath, and a line on each side at apex of abdominal segments 

 1 — 4 above, long and almost meeting on middle of first segment, those on the 

 other segments becoming gradually shorter, white; metathorax coarsely reticu- 

 lated, the spines prominent and subacute ; tegulse generally rufo-testaceous; wings 

 subhyaline, in the posterior pair the anal and diseoidal cells are separated by 

 a short thick transverse, in one specimen longitudinal, nervure; apex of anterior 

 femora more or less, the intermediate and posterior pairs except base, and their 

 tibife beneath, ferruginous ; abdomen short ovate, convex, shining, finely and 

 sparsely punctured, more closely so on apical segments, the second ventral seg- 

 ment more deeply punctured. Length .30 — .35 inch. 



% . — Face and clypeus more densely silvery ; antennae thickened towards tips, 

 the apical joint, truncate at tip and subemarginate beneath; legs black, with apical 

 half of posterior femora only, ferruginous; abdomen more closely punctured, the 

 apical segment above truncate at tip, with the sides obtusely produced and tufted 

 with short pale pubescence. Length .32 inch. 



Hah. — Washington Territory, (Morrison). Three specimens. This 

 has an unusually robust form. 



Nysson alboinarginatus n. sp. — 9 -—Black, opaque; head and thorax 

 closely and somewhat confluently punctured; space between ocelli not raised; 

 mandibles ferruginous near tips; posterior margin of prothorax, tubercles, an 

 arcuate line on base of scutellum, spot on sides of coxse, line at tip of four anterior 

 femora beneath, line on all the tibiae above, two transversely ovate spots near base 

 of first segment above, and the posterior margin of segments 1 — 5 above, more 

 or less dilated at extreme sides, and a spot on disk of apical segment, all white; 

 mesopleura rugose; basal middle of metathorax above with coarse longitudinal 

 rugae, the lateral spine prominent and acute; wings subhyaline, in the posterior 

 pair the anal and diseoidal cells are separated by a longitudinal nervure; abdomen 

 subsericeous, finely and rather sparsely punctured, beneath the second segment is 

 more deeply punctured. Length .30 inch. 



%. — Clypeus with dense silvery pubescence; antennae shaped much as in 9 ^ 

 the scape with a white line beneath : the white spots on base of abdomen much 

 reduced, and the bands on apical margin of the segments not dilated laterally, 

 those on segments 2 — 5 slightly interrupted medially, the two apical segments 



