NATURAL HISTORY OF THE ROCKY MOUNTAINS 47 



Ckll., which occurs on peach. It is, however, certainly distinct, as the skin of P. amygdali 

 is full of large round and oval hyahne spaces, which are not present in the Coulter insect; 

 the latter has numerous small gland orifices, about 5-7 M in diameter, each containing a 

 small central dot. The antennae also differ; for instance, in P. amygdali the second joint 

 is40/t or less in length; in the Coulter insect it is 50. There are also differences in 

 the legs. The rose cottony scale has accordingly been described as Pulvinaria coulteri. 



HYMENOPTERA 



NEW RECORDS OF COLORADO BEES 

 In the genus Nomada the males are often so unlike the females that it is difficult to 

 match them. The male described below very nearly became the cause of a synonym, but 

 fortunately the error was detected. 



Nomada {Xanthidium) collinsiana Ckll. 



6 Length about 10 mm, some slightly more. In my table of Rocky Mountain species, 

 it runs straight to N. luteopicta, but that is a much smaller species, and otherwise different. 

 Head and thorax black, coarsely and as densely punctured as is possible, and clothed vsdth 

 rather long fox-red pubescence, the face, however, not being at all concealed by hair; 

 eyes in life olive-green; head rather broad, the vertex strongly convex, clypeus prominent, 

 facial quadrangle broader than long; clypeus except rather broad upper margin, triangular 

 lateral face-marks (ending in a sharp point some distance below the level of antennae), a 

 narrow line under eye (not going up the cheeks), basal two-thirds of mandibles, and the 

 rather stout scape in front, all bright lemon-yellow; first joint of labial palpi longer than 

 the other three altogether; flagellum stout, black above and bright ferruginous beneath, 

 the joints oblique and very distinct, not denticulate; labrum yellow; thorax entirely black> 

 except that most of the tubercles, and a small spot on anterior part of pleura (not always 

 present) are yellow; tegulae yellow, with a reddish -hyaline margin and discal spot; wings 

 yellowish, dusky at apex, stigma ferruginous, nervures fuscous; basal nervure going a 

 short distance basad of t. m.; second s. m. higher than broad, receiving the first r. n. about 

 its middle ; legs black, yellow, and red ; the hind coxae, trochanters, and femora nearly all 

 black, except a broad, dull reddish stripe, ending in a squarish yellow patch, on hind femora 

 in front; hind tibiae and tarsi red, the former with a yellow mark at end; anterior and middle 

 femora yellow and red in front, behind black and red, with a yellow apical mark; anterior 

 and middle tibiae red and yellow, with a black mark behind; abdomen fusiform, dullish 

 with a minutely tessellate surface, very bright lemon-yellow, with the basal half of the 

 first segment (sending a projection backwards in the middle line) and the extreme (mostly 

 overlapped) bases of the other segments, black; broad apical margins of segments i to 5 

 brown -black; apex with some fox-red hairs; apical plate ferruginous with black edges, 

 narrow, and only faintly notched; venter with four extremely broad, entire bright yellow 

 bands, and a yellow apical spot. Third antennal joint very much shorter than fourth. 



Var. a. Apical plate of abdomen black, broader, and strongly notched. 



Hab. — Boulder, Colo., abundant at flowers of Ribes cereum, flying along with males 

 of Andrena leptanlhi V. & C, which it resembles in the pubescence; April 29, 1905 

 (W. P. and T. D. A. Cockerell). This was taken for a new species, but the day following 

 my wife took a female, which proved to be N. collinsiana, hitherto known only in the 5 sex. 

 The female, when qxiite fresh, has the same red hair on the head and thorax as the male. 



