342 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxi. 



is rendered more noticeable by the fact that the contents of the type 

 have been n^nioNcd l)y iiiuseiiin pests. In the specimens of atratum 

 studied, all shades of color from a jet blaciv to the })ro\vn of hrimnipes 

 occur, and I must therefore re^j-ard the latter as a color subspecies, 

 most abundant in the southern States though one specimen fron Mon- 

 tana is also of this shade. 



This insect is well illustrated in Howard's Insect Book, Plate V, 

 % 20. 



CHLORION (PRIONONYX) THOM^E (Fabricius). 



Sphex thomxYA^Riciv?,, Syst. Ent., 1775, p. 346. 



? Pepsis crucis Fabricius, Syst. Piez., 1804, p. 209. 



Pepsis thomie Fabricius, Syst. Piez., 1804, p. 209. 



Prionoityx thomx 'DMU.mni, Hym. Eur., I, 1848, p. 28. 



Prianorujx thomsc Dahlbom, Hyni. Elur., I, 1845, p. 439. 



Priuno7n/x thomfe Smith, Cat. Hym. P>rit. ]\Iu.s., IV, 1856, p. 265. 



Enodia puJndnn^um A. Costa, Ann. Mus. Zool. Napoli, I, 1862, p. 69. 



JVioriony.i- </(OHuc Saussure, Reise d. No vara, Hym., 1867, p. 43 (in part). 



Priononyx tliomae Cresso^, Trans. Am. Ent. Soc, IV, 1872, p. 213. 



Sphex thomse CAMEROii, Biol. Centr.-Ainer., Hym., II, 1889, p. 36, pi. iii, figs. 12 



and 12a. 

 Spliex {Harpactopus) tliom.r Koni,, Ann. natur. Ilofnuis. Wien, V, 1890, p. 358. 

 Sphex {Priononyx) thovur Fox, Proc. Acad. Nat. Sci. Phila., 1897, p. 378. 

 Sjihex thomx Ducke, Zeits. f. Syst. Hym. u. Dipt., I, 1901, p. 241. 



Black, to and includino- the petiole; abdomen more or less ferru- 

 ginous; pubescence silvery white to j^ellowish white; wings quite 

 hyaline, faintly fuliginous. 



Female. — Head large, quadrangular when viewed from above; front 

 slightly excavated between the eyes; clypeus and frons well covered 

 to about the level of the ocelli with 3'ellowish-white pubescence, least 

 so in the middle; clypeus broad, with a marked median notch, the sur- 

 face around which is depressed; surface of the cljqoeus with a few 

 coarse, and many line punctures; this plate and the lower part of the 

 frons with many long, coarse, white hairs, becoming smaller and 

 shorter above; frontal suture present but not strongly developed; con- 

 tinued faintly between the lateral ocelli; an oblique suture is present 

 on each side of the ocelli; distance between the lateral ocelli about 

 equal to their distance from the eyes; surface around the ocelli and on 

 the vertex whitish sericeous, continued over the cheeks; these are 

 quite full but not as broad as the width of the eye; narrowing quickly 

 below; with man}^ long, white hairs below and a few smaller ones 

 above and on the occiput; eyes parallel in front; antenna? black, gra^nsh 

 sericeous on the filament; scape whitish sericeous over a dull, faint 

 ferruginous tinge; with a few short hairs on its tip inside; relative 

 lengths of lilament segments ^V, A^ t\, t¥, A; mandibles black, with 

 a dull ferruginous cross band near the base of the teeth; with three 

 teeth, the middle one smallest; mandible long, reaching about to the 



