AMERICAN HYMENOPTERA. 235 



the description oi' niorio (Trans. Am. Ent. Soc, 1865, p. 486) shows 

 that the present species cannot be concolor ; e.g. in that species the 

 abdominar petiole is one-half of the rest of the abdomen, which is 

 called "broadly ovate"; in tinctipennis the petiole is not one-fourth 

 of the length of the abdomen, which is, moreover, longish ovate. 



Passaloecus niaiidibiilariis Cress. 

 Pemphredon mandibularis Cresson, I'roc. Ent. Sue. Phil., iv, 487. 



Three Rivers, California. 



^ BEMBBCID^. 



Monedula <lenvereiisi!>i sp. nov. 



Lemon-yellow, the head paler; the iipperside of the flagellum of antenoa;. the 

 occiput except round the edged, a baud on the outer edge of the vertex behind 

 the ocelli from the outer edge of which a stripe runs down near to the antenna, 

 its upper (and smaller) part being oblique, narrowed below, the lower runs 

 straight down, is wider, is straight on the outer side, roundly narrowed on the 

 inner, a large mark in the centre of the pronotuni at the base, the apex of which 

 has three small dilations, a narrow line runs from its base to the outer edge, the 

 mesonotum except the sides and two longitudinal lines in the middle, narrowed 

 towards the apex ; a broad line, dilated laterally on the apex of the scutelluni, a 

 narrow line on its ape,s, a curved line on the base of metanotuni from the outer 

 edge of which a line runs obliquely to the a})ex, in the centre of which the two 

 lines unite, a line down the apex of the niesoplenrse, a line down the base of the 

 metapleurse, this line being prolonged towards the middle below, the basal siojie 

 of the first abdominal segment, its middle at the apex narrowed into a huge 

 squarish mark, with the outer apical edges produced outwardly, the base of the 

 second, third and fourth segments broadly, the line on the second shortly dilated 

 in the middle, with a transverse line, more than three times its length at the 

 end; the line on the third is broadly dilated in the middle, this part having a 

 square incision in the middle of the apex, the outer edges of the maik being 

 dilated outwardly at the apex, a broad line, roundly incised in the middle, at the 

 apex on the fourth and fifth, the apices of the basal three segments and irregular 

 bands on the apices of the third to fifth apical segments, black ; the centre of the 

 second dorsal behind the transverse line, the apical half of the third and irregu- 

 lar spots in the centre of the fourth and fifth rufous. liCgs of a brighter yellow 

 color than the body, the basal half of the femora broadly black above. Wings 

 clear hyaline, the uervures and stigma fulvous. 9 • Length 14 mm. 



Head and thorax covered with white pubescence, that on the bead the longer. 

 A longish, wide furrow above the ocellus, which is bordered and longer than 

 wide, rounded behind. Upper part of the body closely, minutely punctured. 

 Second cubital cellule square, of equal width, the nervures parallel. Pygidium 

 strongly, distinctly, but not very closely punctured. Wings as long as the head 

 and thorax united. 



Denver, Colorado. 



This species is related to M. speciosa Cress. The differences be- 

 tween the two may be expressed thus : 



TRANS. AM. ENT. SOC XXXIV. JULY, 1908. 



