Studies of North American Bees 5 



Allotype.— Type lot (No. 8140, O. A. Stevens), J*. 



Paratypes.— Type lot (Nos. 8136, 8138, 8139, 8141), 3 ?, i c?; 

 type locality, May 30, 1914, on Zisia aiirea (No. 8037, O. A. 

 Stevens), i (^; do., June 21, 191 3, on Zisia aurea (Nos. 5162, 

 5165, O. A. Stevens), 2 J^; do., June 22, 1913, on Zisia aurea 

 (Nos. 5329, 5330, O. A. Stevens), 2 J*; do., June 22, 1913, on 

 Rubus strigosus (Nos. 5278, 5279, O. A. Stevens), 2 J'. 



A member of the sayi group, and is possibly only a northern 

 subspecies of N. sayi Rob. The 5 differs from A^. sayi Rob. 5> 

 however, in its darker red color, more extended black markings 

 of head and thorax, and distinctly tuberculated outer margin of 

 hind tibiae ; the J* easily differs from sayi J* also in its darker 

 color, red areas on mesoscutum, and little or no clear yellow 

 color on the face or legs. It differs from N. propinqua Swenk 5, 

 in the same characters as from N. sayi; however, the ^ differs 

 from the supposed J* of propinqua (which may not really be the 

 other sex of propinqua) in much smaller size, sharply pointed 

 mandibles, largely reddish testaceous instead of wholly yellow 

 head and front leg markings, lack of yellow on tergite 6, black 

 metanotum, etc. A^. florilega Lovell and Cockerell 5, has much 

 more black color on the head and pleura, and the propodeum is 

 wholly black. A^. ceanothi Ckll. 5, difl'ers distinctly in its shorter 

 third antennal joint, less prominent mesoscutellum and wholly 

 black propodeum. A^. oregonica Ckll. 5, is distinct in its trin- 

 lineate mesoscutum, longer third antennal joint and simple meso- 

 scutellum ; oregonica J* is readily separable by having the thorax 

 without red, except on the tubercles, and a more yellow-spotted 

 abdomen. N. hifurcata Ckll. J*, differs in the wholly black 

 thorax, the black scape, and . the paler red and more yellow- 

 spotted abdomen. N. zvootonella Ckll. J*, may be separated by 

 the subentire apex and broad, interrupted yellow bands on tergites 

 2 and 3. A^. Ichighensis Ckll. J*, which is not very closely related, 

 may be separated by the longer joint 3 and shorter joint 4 of 

 antennae. 



Nomada (Nomada) obstusata n. sp. 



$. Length 6.5-7.5 mm- Dark red ; a large quadrate spot above and 



159. 



