42 Messrs. T. D. A. Cockcrell and E. Atkins on 



tlie wings, whereas the Panurginse have but two ; however, 

 Nomada ohliterata, Cresson, has constantly only two sub- 

 marginals *, while a form of Dufourea (subg. Trilia, Vachal) 

 has three. Andrena has usually three submarginals, but 

 some species have only two. 



As typical examples of iVowacZa we have studied N. fucatUy 

 Panz. (Mallorca, Balearic Is., from Friese), and A^. xantho- 

 jdiila, Ckll. (New Mexico). In Panurgus we have used 

 r. calcaratus and P. Banksianus. 



Nomada modesta, Cresson (Las Vegas, N. M., collected by 

 A. Garlick), differs from the other species by the very large 

 and long galea (actually larger than in N. xanthophila, 

 though the bee is smaller), shorter maxillary palpi (not much 

 over half length of galea), very long paraglossje, long tongue, 

 and very long basal joint of labial palpi (much exceeding the 

 other three joints together). In these characters (except the 

 paraglossaj) N. modtnta closely resembles CalUopsis verbence 

 (also from Las Vegas, N. M.). 



There is a singular resemblance in the mouth-parts between 

 Nomada and Exomalopsis, but the bees are otherwise 

 entirely different, and are evidently not related. 



The following table gives the differential characters of the 

 mouth-parts of several Panurgine bees, placing Nomada 

 among them for purposes of comparison : — 



A. Maxillai'y palpi far surpassing the galea f. 



ft. First joint of labial palpi longer than the 



other three together ; galea broad, 



not bristly Ilalictoides dentiventris, 



aa. First joint of labial palpi not longer [N^yl. 



than the other thi'ee together. 

 b. First joint of labial palpi about equal 

 with second ; the hrst two joints 



very stout Mhophitoides caims 



hb. First joint of labial palpi couspicu- [(Eversm.). 



ously longer than second. 

 c. Tongue very narrow, nearly parallel- 

 sided ; labial palpi long and slen- 

 der ; galea very slender apically, 

 with bristles along its whole hind 



* Nomada obliterata may stand as the type of a subgenus Hemi- 

 nornada. — T. D. A. 0. 



t The maxillary palpi also surpass the galea in SpinoKella scitula 

 (Cresson) and HylcBosuma atriceps (Cresson), species formerly referred to 

 Calliojjsis. In the Spinoliella the first joint of the labial palpi is very stout 

 and longer than the other three together ; in the Hylccosoma it is scarcely 

 as long as the other three together. In both the galea is broad and 

 bristly at the apex. — T. D. A. C. 



