AMERICAN HYMKXOPTEllA. 227 



furrow in the centre of the front. Tiiorax strongly, closely i)nnctured, the ))uuc- 

 tuation on the mesonotum running into reticulations. There is a narrow black 

 furrow down the middle of scutellum. The apex of the postscutellum is more 

 rounded than the base. Base of thorax above bluntly rounded, the sides 

 rounded, not projecting. The second and following segments of the abdomen 

 are closely, distinctly punctured ; the ai)ical half of the second is depressed, the 

 depression dilated backwards in the middle. 



Oslar, Berkeley, Colorado. 



This species agrees very closely in coloration with '^-fuHciahis, but 

 is smaller and more slenderly built. 



The rounded, not projecting lateral angles of the pronotun) ibrm 

 a ready means of separating this species from 5 fasclutus. 



The two may be separated thus: 



Apex of clypeus incised; the front immaculate; clypeus broader than long; 

 apex of postscutellum transverse, base of thorax trans'^erse. the lateral 

 angles acute 5-faseiutus. 



Apex of clypeus transverse; the front with a large triangular red mark; the 

 clypeus nearly as long as broad ; a|)ex of postscutellum rounded ; base 

 of thorax bluutly rounded, the angles rounded Illiirulif 1M»II.«>. 



^ Pterochiliis priiiiiosiis sp. nov. 



Black, densely covered with a whitish pile; the clypeus, except narrowly 

 round the apex, a mark, with its upper half broadly dilated, over the antenna?, 

 a line round the eye incision, the outer orbits, broadly above, the mark gradu- 

 ally narrowed below, the base of thorax, the line extended broadly to the mid- 

 dle of propleurse, tegulse, two irregular marks on the scutellum, laterally ex- 

 tended at the apex to the wings, postscutellum. a large irregular mark on the 

 sides of median segment, broad lines on the apices of the abdominal segments 

 (that on the first broader and more irregular than the others) and a large conical 

 mark on the top of the base of the mesopleurte, followed below by a longer, nar- 

 rovver irregular stripe, pale yellow. Legs reddish fulvous, the coxEe, trochanters 

 aud base of femora black ; the four anterior coxje spotted with wliite below ; the 

 apex of t|ie middle femora and the outerside of the four hinder tiliise are broadly 

 white. Wings hyaline, the costa and stigma dark fulvous, the nervures black. 

 9 . Total length 9 mm. 



Head clearly wider than the thorax ; the tenijiles obliquely roundly narrowed ; 

 the occiput roundly incised. Clypeus much broader than long; its apex broadly 

 projecting, transverse, red, with a black, irregular transverse line above. Front 

 closely and strongly, the vertex weakly, the clypeus more strongly, sparsely 

 punctured. Base of thorax transverse, with projecting angles. Base of postscu 

 tellura transverse, the apex more rounded. Thorax closely, strongly punctuied, 

 except on the metapleurse, where it is smooth. Abdomen strongly and closely 

 punctured; the first segment cup-shaped ; its apex with the punctuation strong 

 and sparse. Palpi long, broad, yellow, tinged with rufous; the hair very long, 

 yellowish-white. Mandibles red, broadly yellow at the base; there are only two 

 distinct teeth. 



Oslar, Prescott, Arizona. 



TEANS. AM. ENT. 80C. XXXIV. JULY. 1908. 



