24 E. T. CRESSON. 



scutellum, two dots and short line behind, coxse, trochanters, femora, except 

 black spot at tip of posterior pair, tibiae, except line on anterior pair behind, 

 and tips of two posterior pairs, triangular spots at extreme sides of abdominal 

 segments above, spot on apical segment above, and narrow apical margin of 

 ventral segments, all yellow or yellowish-white; wings faintly dusky, nervures 

 and stigma black, the latter pale at base. Length .35 inch. 



y var. — Spot on sides of pleura very large; wings clearer; line on anterior 

 legs above, spot at tip of intermediate femora, line on their tibiae and inter- 

 rupted line on posterior femora above, black. Length .40 inch. 



Hnb. — Colorado, Nevada, (Morrison). 



Tenthredo vittatipes. — %. — Black, shining; head beneath antennsB, 

 spot at summit of eyes, scape beneath, most of prothorax, pectus, pleura except 

 oblique line beneath wings, legs except black stripe above, venter and lateral 

 margin of dorsal segments, greenish-white; head much broader than thorax, 

 face deeply impressed, eyes large and prominent; tips of mandibles black; 

 flagellum obscure pale beneath; wings hyaline, nervures and stigma black; 

 posterior tarsi mostly black; abdomen depressed. Length .30 inch. 



Hah. — Nevada, (Morrison). Four specimens. This may prove to 

 be the % of addenda. 



Tenthredo rubens. — %. — Black, shining; head smaller, more trans- 

 verse than usual; sometimes a slender line on upper anterior orbits, and 

 labrum white; palpi aud antennse beneath pale testaceous, the latter longer 

 than usual; thorax entirely black, except sometimes a pale line on upper 

 posterior margin of prothorax, a dot on tegulse, or two dots on scutellum ; 

 clypeuB not emarginate, third joint of antennae longer than fourth; legs 

 ferruginous, anterior pair and tarsi paler, coxae, trochanters, and base of 

 femora, black; wings smoky hyaline, nervures black, stigma and costal nerv- 

 ure more or less yellowish; abdomen ferruginous, basal 7)lates and sometimes 

 the two or three apical segments black. Length .32 — .40 inch. 

 Hab. — Nevada, (Morrison). 



Tenthredo diluta. — f. — Ferruginous; head smaller than usual, not 

 broader than thorax, clypeus not emarginate; clypeus, labrum, base of mandi- 

 bles, upper lateral margin of prothorax, scutellum, spot above posterior coxae, 

 and most of the cox£e and trochanters, white; pectus with a black spot before 

 middle coxae; antennae slender, as long as head and thoiax, third joint longer 

 than fourth; wings faintly dusky, stigma yellowish, under wings without 

 middle cell; tarsi mostly pale yellow. Length .40 inch. 

 Hah. — California, (Crotch). 



Tenthredo Edwardsii. — J .—Shining-black; head a little narrower 

 than thorax; orbits, interrupted behind near summit of eyes, spot between 

 base of antennae, clypeus, labrum, base of mandibles, palpi, broad upper 

 margin of prothorax, scutellum more or less, tegulse, elongate spot on sides of 

 pleura, spot above posterior coxae, all the coxae and trochanters more or less, 

 anterior legs in front, and the posterior tarsi, all yellowish-white; wings sub- 

 hyaline, dusky on apical third or half, nervures black, stigma except base, 

 and the costal nerve, yellowish ; second recurrent nervure generally coinciding 

 with second transverse cubital nervure, second submarginal cell receiving the 



