IK). 1124. REViaws or lUE Mt:LASuvu-scn)UEH. 3Ul 



apinti third as parallel, cyliiidrical but tap< ^ill^^ acniniiiate needloii*^ 

 reaching to tiic diMtal (MuI of tiie middle thinl of tlii> siipiaanal plate; 

 <'er(!i Mlciidcr feebly eoinpresHi'd laminae, rapidly narrow iii|x on basal 

 third, the middle third equal, hardly compreHsed atul half as broad an 

 extreme base, then expanding? to a nearly e(piul extent to form a eom- 

 pressed, spatnhite, ineurved tip, the apical portion of which is very 

 strongly <'ompres8ed and not in<nrved; infracercal platcH bntadly 

 rounded apically, as Ion;; as the supraaiuil plate; Hub;^enital plate mod- 

 erately broad, sube«|ual in breadth, considerably lonjjer than broad, 

 feebly tlariiij^, the apical mar;;in very broadly an<l feebly elevated, well 

 roundoil but feebly annulate, entire. 



Length of body, male, J."* nnn., female, *-*8 mm.; antennae, n»ale, 12.5 

 mm.; tei^mina, male, \\)t mm., fennde, 21 mm.; hind femora, nmie, 12.75 

 mm., female, 14. 2o mm. 



One male, 1 fenmle. Grand Canyon of the Colorado, Arizona, July 

 10 (L. Hruner). 



This species is rather rloaely allied to the last, M. complanatijus, i)ut 

 is easily distinguished from it by its less stron^jly compressed hind 

 femora with their bifasciate markings. The dit^erences in the abdom- 

 inal appenda^a»8 are slight, but are found at every point. 



21. ANGUSTIPENNIS SEIUES. 



A very homofjeiieous group (and one very closely allied to the i)re- 

 ceding), in which the prozona of the male is variable, and the interval 

 between the mesosternal lobes in the same sex varies tVom a little 

 longer to several times longer than broad. The tegmiiia are always 

 fully develoi)ed ami reach or somewhat surpass the tips of the hind 

 femora. The hind tibiae are red or glaucous and have from nine to 

 thirteen spines in the out-er t^eries. 



The supraanal plate is long and rounded triangular, and j»reapically 

 contracted somewhat conspicuously. The furcula consists of a i»air of 

 slender, tapering, acuminate lingers of considerable length, generally 

 extending over a third of the supraanal plate. The cerci are rather 

 short and rather slender, incurved or inbent ai)ically, spatulate, not 

 nearly re 'hing the tip of the supraanal plate. The subgenital plate is 

 large, fully as broad as long, not or but little elevated ai)ically and 

 there usually feebly notched. 



The species, only four in number, are of medium or rather small, 

 occasionally rather large size, and occur from Iowa to Utah, and from 

 Montana and Manitoba to Texas, though one spe<'ies ranges r.s far east 

 as Sudbury, Ontario — the only one found east of the Mississippi. They 

 occur mostly in the region between the Kocky Mountains and the Mis- 

 sissippi. ; ;_.. . . -^ . 



