562 PROCEEDINGS OF THE ACADEMY OF [Aug., 



middle tibia wholly 5^ellow, posterior tibiae yellow with a small black 

 , stripe behind, all the tarsi yellow. The second and third submarginal 

 cells are considerably contracted above, and the basal nervure ends 

 only slightly basad of the transverso-medial. The postscutelliim has 

 a short j^ellow stripe. 



Hab.— Three males labelled "So. Cal." (Coll. Acad. Nat. Sci. Phil.). 

 Named after Mr. Hemphill, the well-knoAvn naturalist of San Diego, Cal. 



Nomada (Holonomada) excurrens, sp. n. 



cJ*. — Length about 12 mm.; black and yellow. Similar to TV. hemp- 

 hilli, except that the apical plate of the abdomen is broader and 

 strongly notched (in hemphilli it is quite entire), and the transverso- 

 medial nervure is strongly oblique (only slightly so in hemphilli). The 

 hind tibiae are entirely yellow, without the black stripe seen in hemp- 

 hilli. 



Hab.— "So. Cal.," one (Coll. Acad. Nat. Sci. Phila.). This is so 

 close to N. hemphilli that it may prove to be only a variety ; yet it has 

 characters which would exclude it from Holonomada, as that group is 

 defined by Robertson. 

 Nomada (Holonomada) edwardsii, Cresson. 



i7a6.— Santa Clara county, Cal. (Coquillett). In Coll. U. S. Nat. 

 Museum. 

 Nomada (Holonomada) edwardsii var. australior, v. nov. 



(^. — Length 11 mm.; black and yellow. Differs from edwardsii by 

 its smaller size; supraclypeal mark larger (broader than long); lateral 

 face-marks convex on the inner side and pointed above (concave on 

 inner side above clypeus, and obliquely truncate above, in edwardsii) ; 

 third antennal joint shorter, and paler beneath; ventral surface of 

 abdomen wholly yellow beyond the second segment. The apical plate 

 is entire, and the metathorax has a pair of yellow spots. From N. 

 citrina it differs thus : Posterior orbits only very narrowly yellow, and 

 that little more than half-way up ; no yellow spot below middle ocellus ; 

 flagellum black above, dull red beneath; third antennal joint a little 

 longer than fourth, the two together a little shorter than scape, etc. 

 The hind femora are practically all black behind, and all the tibiae have 

 much black behind. 



Hab. — Los Angeles county, Cal. (Coquillett). In Coll. U. S. Nat. 

 Mtiseum, Perhaps a distinct species. 



Nomada (Holonomada) rhodotricha, sp. n. 



9 . — Length about 13 mm., build of N. superba; black and red, 

 abdomen with broad chrome-yellow or orange bands. Head and 



