Studies of North American Bees 21 



cell less narrowed above. Abdomen uniform light red, tergite i with a 

 basal trilobed black mark, sometimes with small yellow spots, spots on 2 

 and 3 extending considerably mesad on the tergites, 4 sometimes with faint 

 lateral spots, apex deeply notched. 



Type. — Fargo, North Dakota, June 22, 1913, on Rubus 

 strigosus (No. 5275, O. A. Stevens) J*. 



Allotype.— Type lot (No. 5276, O. A. Stevens), ?. 



Paratypes. — Type locality, June 15, 1913, on Zisia aurea (C. 

 H. Waldron, Nos. 4996 and 4997, O. A. Stevens), i J*, i $ ; do., 

 June 21, 1913, on Ruhus strigosus (No. 5135), i $; do., June 22, 

 1913, on Zisia aurea (Nos. 5316 and 5324), i 5, i J*; do., on 

 Erigeron philadelphicus (No. 5334), i J*; do., June 17, 1914, on 

 Zizia aurea (No. 8080), i 5; do., June 20, 1914, on Thlaspi 

 arvense (No. 8114) i 5; Detroit, Minnesota, June 17, 1911, on 

 "Zisia and Sanicula" (C. H. Waldron, No. 2373, O. A. 

 Stevens), i $. 



A member of the schzvarsi group, and, possibly, only a sub- 

 species of A'', schzvarsi Ckll. Apparently distinct from N. 

 schzvarsi J*, however, in mesoscutum being wholly red except 

 for the black median band and the narrow anterior and posterior 

 margins (mesoscutum merely with four red lines in schzvarsi), 

 the mostly red mesopleura (merely red-spotted in schzvarsi), red 

 postocular and occipital bands and sides of vertex (black in 

 schzvarsi) and lack of blackish suffusions on the apical tergites. 

 In the largely red mesoscutum and mesopleura it is approached 

 by N. schzvarsi contractula Ckll., but that form differs in the 

 feebly notched apex, dark red ground color of tergum, and 

 shorter third antennal joint. The frequently red-spotted or red- 

 banded propodeum differs from either schzvarsi or contractula, 

 which have the propodeum entirely black. From N. schzvarsi 5 

 (Ute Creek, Colo., June 27, 1907) the $ differs chiefly in the 

 darker red color and spots on sides of tergite 3. A'', ruhrella 

 Ckll. J* is also very close, but differs in its creamy-white instead 

 of pale yellow markings of the face and abdomen, red sides of 

 propodeum, less black at base of tergite i, and less strongly 

 notched apex. From N. cornelliana and N. physnra Ckll. the J* 

 differs in somewhat smaller size, more extensively red thorax 



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