1896.] NATURAL SCIENCES OF PHILADELPHIA. 35 



common at Saata Fe, but yields no Perdita. The constancy 

 of Perdita spp. to their proper flowers was well illustrated at 

 Albuquerque, where on the Cruton was only P.crotonis, while 

 on the Cleome only 8 paces distant was only P. zebrata. At 

 Las Cruces, Croton neomexicanus is common, but I found on 

 it no Perdita, or even bees, only Larridse and especially Phil- 

 anthidce, including Aphilanthops taurulus. This was on Sep- 

 tember 25th, and only staminate flowers were to be found. 

 Croton is a very large genus, with many neotropical species, 

 but also found in the tropics of the Old World. 



MALVACEiE. 



(9). Sph^ralcea angustifolia Spach. Abundant and variable 

 from Las Cruces to Santa Fe, in the former locality furnish- 

 ing P. latior and P. sphceraleece ; in the latter a distinct race 

 of sphceralcecB. At Santa Fe the Sphceralcea is visited also by 

 Epeohis, Bombxis, Colletes, Melissodes, etc. At Las Cruces it 

 is principally visited by Dladasia. 



LOASACE^. 



(10). Mentzelia nuda (Pursh) Torr. and Gray. Visited at Santa 

 Yi by P. mentzelke, and at Albuquerque by P. paUidior and 

 pulchrior. It is a favorite i?ow6its flower. The genus goes 

 south to Chili. 



UMBELLIPERiE. 



(11). Hydrocotyle umbellata L. Mr. Robertson reports P. 

 obscuraiaiYom this. I have never myself found any Perdita 

 on an Umbellifer. 



SOLANACE^. 



(12). Cham^saracha coronopus (Dunal) A. Gray. P. cIuwkb- 

 sarachce abounds on this at Albuquerque, and was also taken 

 on it at Santa Fe. The genus is a small one, the Index 

 Kewensis cites 1 Texas, Mexico, 2 California (here includiug 

 our coronopus), 1 Mexico, and 1 Japan. Thus it is not ap- 

 parently of neotropical origin. 



COMPOSITE. 



(13). GuTiERREZiA SAROTHK.E (Pursh) Britt. and Rusby. At 

 Albuquerque were found on this, one each of P. austini, 

 gutierrezice and pallidior — the last doubtless accidental. 



(14). GuTiERREZiA SAROTHR.E var. MiCROCEPHALA (Gray) Coul- 

 ter. This is common at Las Cruces, and has furnished P. 

 austini, semicrocea, luteola, phymatce, tarda and cladothrieis. 

 On September 25th, a single 9 verbesince was also taken on 



