290 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 38. 



white hair al the bases of the segments, more or less covered by the 

 hyaline apices of the segments before. 



Paranomia Friese (type, chalybeata Smith, from China) includes 

 the species with colored pearly bands on the abdomen, represented 

 in America by the group of X. nortoni. Hoplonomia Ashmead is 

 similar, but has a bidentate process or two teeth on the postscutellum. 



Epinomia Ashmead (type, triangulifera Vachal) should probably 

 be extended to include the group of N. nevadensis. This is the mosl 

 " normal " of our groups of Nomia, in the sense of being less divergent 

 from other bees. 



Dieunomia (type, marginipennis Cresson) consists of large species, 

 in which the last antenna! joint is broadened and flattened. A', bol- 

 liana, a smaller species just described, must also be referred here. 



It would not be illogical to exclude Nomia from the American fauna, 

 and recognize three genera, Paranomia, Epinomia, and Dieunomia : 

 but in this case it would be necessary to decide what to do with the 

 numerous African, Asiatic, and Australian species, which in various 

 ways seem to connect the segregated genera with true Nomia, or in 

 some cases form what might be regarded as other genera or subgenera. 

 1 have a considerable series of these foreign insects and am at a loss 

 to know how to satisfactorily divide them into genera. The group is a 

 peculiar one, and apparently its little morphological jokes must not 

 be taken too seriously. 



Perhaps the most significant distinctions are to be found in the 

 mouth parts. In the type of the genus, Nomia diversipes, I find the 

 tongue short, broad at the base, rapidly narrowing to a linear tip. 

 The labial palpi have the first joint much shorter than the other three 

 combined (proportions about 13 to 20), and the maxillary palpi extend 

 beyond the maxillary blade, which is very bristly at the end. In 

 Nomia nevadensis the conditions are essentially the same, but the first 

 joint of the labial palpus is to the others combined as about 13 to 18, 

 the apical joint being shorter. In N.foxii the first joint of the labial 

 palpus is to the other three combined as about 20 to 22, approaching 

 equality, while the tongue is considerably elongated, gradually taper- 

 ing, its length about 1,275 ft, its width at base about 220, not counting 

 the hair. 



The following figures give the lengths of the joints of the labial 

 palpi in microns. For the first joint only the dark chitinized part is 

 measured. 



Labial palpi, joints 



..; triangulifera. 



oes... 

 Nomia foxii... 



(1) 



510 

 220 



.'jn 

 ::iu 





L".'(l 

 100 

 100 

 127 



(3) 



'.'ill 

 IIK) 

 llll 



127 



(4) 



220 

 100 

 L36 

 12? 



