148 HYMENOPTERA. 



clypeal area. The tegulae may or may not have yellow. 

 The affinity of this species is undoubtedly with P. wootoni, 

 from which it is only distinguished by the dark supraclypeus 

 and the long basal lobes of the seventh ventral plate. Ap- 

 parently, however, these characters are constant in all speci- 

 mens. The variations in the markings of the female are not 

 as noticeable as in the male, but in this as in the other sex 

 the lateral marks are always long. Occasionally a specimen 

 is found with a yellow spot on the clypeus, but never very 

 conspicuous. This sex can only be separated from P. zvootoni 

 females by locality, which is not at all certain. 



PROSOPIS NEVADENSIS Ckll. 1896. 

 1896. P. nevadensis, Ckll. Psyche Supp. 7:32. 

 1898. P. nevadensis, Ckll. Ent., 1898, p, 185. 



1910. P. hesperiphila, Ckll. Ann. and Mag. Nat. Hist. Ser. VIII. 

 5:29. 



Male. — Small ; very similar to P. polifolii Ckll., but can be distin- 

 guished by its broader face, short broad lateral face marks, and very 

 different genitalia. 



About 5 mm. long. Face broad above, narrowing suddenly below ; 

 clypeus narrower at base than lateral areas at same level, and about 

 twice as broad at apex as at base. Antennae and general structure as 

 in polifolii. 



Sculpture. Punctures of head, thorax, and abdomen dense and 

 heavy as in polifolii. 



Yellow Markitigs. — Lateral face marks broad, filling lateral areas, 

 following antennal sockets for about one-fourth their circumference ; 

 truncate at about the level of top of antennal sockets, with a slight 

 projection at eye margin, (fig. 115). Collar, tubercles, tegulse, and 

 wing bases normally with yellow. 



Genitalia. — Armature short, stout ; cardo rather short ; stipes stout ; 

 superior lobe extending half-way to apex ; apical portion stout, taper- 

 ing at tip, rather heavily haired ; volsella large, especially lateral lobe; 

 sagittal rods equal in length to stipites, (fig. 22). Seventh ventral 

 plate unlike that of any other species. Each wing is rather long, uni- 

 form in width thruout, curving out gradually at base where it is 

 rounded, without any basal lobe; basal portion sparsely covered with 

 rather long delicate hairs ; apex of each wing a membranous flap ex- 

 tending outward or forward, (fig. 61). Eighth ventral plate short, 

 stout ; distal pedicel stout, ending in two apical lobes, pubescent at 

 tips, (fig. 62). 



Female. — Similar to same sex of P. polifolii^ but has short lateral 

 face marks, (fig. 121). 



