Studies of North American Bees 55 



Nomada (Nomada) subpacata n. sp. 



$. Length 7 mm. Red ; oval spots behind antennal bases encroaching 

 down on sides of supraclypeus, oval spot involving ocelli, cheeks behind, 

 prothorax except collar, anterior and posterior margins of mesoscutum 

 and a narrow, medially indistinct mesoscutal line, metapleura and contig- 

 uous edge of propodeum, area under wings, depressed sides of meso- 

 scutellum, metanotum except a transverse line, median line on propodeum, 

 spots on coxae behind, on femora beneath and on tibiae within, black. 

 Abdomen black above, the very apex of tergite i slightly stained with 

 reddish and the lateral apical margins of tergites 2 and 3 and whole mar- 

 gin of 4 narrowly reddish testaceous, large cuneate white spots on sides of 

 tergite 2, smaller spots deeply emarginate posteriorly on sides of 3 and 4, 

 a large transverse white spot on 5 with a small lateral spot cut off on each 

 side. Venter red, with discal medially interrupted white bands on stern- 

 ites 3 and 4. Pygidial area acute, finely and closely pale haired, the sides 

 of segment 6 with tufts of long curved black bristles. Antennae red, 

 the flagellum above somewhat obfuscated apically, antennal joint 3 a shade 

 shorter than 4. Clypeus and cheeks finely and closely punctured, rest of 

 head and thorax coarsely and closely punctured, body practically devoid 

 of hair. Tegulae shining, reddish testaceous. Wings slightly clouded, 

 darkened on apical margin, basal nervure basad of transverso-medial. 

 Outer face of hind tibiae strongly tuberculate, the apices each with about 

 four small straight setae. 



Type. — Fargo. North Dakota, September 16, 191 1, on Aster 

 exignus (O. A. Stevens, No. 3018). 



This species is close to A'', accepta {^pacata Cresson), but 

 apparently is distinct in its smaller size, in the lack of the 

 yellowish white spots on the sides of the face below and on the 

 base of the enclosure, in having the first abdominal tergite 

 wholly dark (in accepta there is a whitish interrupted band behind- 

 which the tergite is red), the abdominal maculations whiter and 

 more widely separated on tergites 2-4, and the mesoscutum with 

 merely a narrow median line (usually distinct lateral lines in 

 accepta). From A', gutierreziae Ckll., it dififers in the much 

 shorter third antennal joint, lack of a pale band on tergite i, etc., 

 and from A', libata Cresson, A^ vallesina Ckll. and A', coloradcnsis 

 Ckll., it differs at once in the white rather than yellow maculations 

 and in other characters. 



55 



