744 THE AMERICAN NATURALIST. [VOL. XXXIX. 



dish brown. It must be similar to D. sphceralcearnm, but the 

 antennae are differently colored. 



The following species are not considered valid : 

 D. tricincta Provancher, from California, is said by Fowler to 

 be a synonym of enavata. This cannot be, from the descrip- 

 tion ; but it is not apparent that it differs from afflicta. D. 

 nerea Fowler, from California, is nigrifrons Cresson ; D. cinerea 

 Fowler, from California, is bituberculata Cresson. Fowler can 

 hardly be blamed for describing these as new, as when he pub- 

 lished his paper Cresson's species were supposed to belong to 

 Melissodes. D. ursina (Cresson) is enavata. D. apacha (Cres- 

 son) is diminuta. The types of apacJia have been in some 

 liquid, presumably alcohol, and this accounts for part of their 

 characters. I formerly separated the specimens of the Middle 

 Sonoran zone as apacha, leaving those of the Upper Sonoran as 

 diminuta ; but the comparison of specimens from various locali- 

 ties appears to show that the characters relied upon are too vari- 

 able to serve for specific distinction. 

 Two forms are new : 



Diadasia afflicta (Cr.) subsp. perafflicta n. subsp. 



$ Tegulae piceous ; second submarginal cell scarcely narrowed above ; 

 hair of meso thorax and scutellum gray. 



? . This sex does not materially differ from true afflicta. 



Hab. Clark Co., Kansas, 1962 ft., May (F. H. Snow, 1191) ; Hamilton 

 Co., Kansas, 3350 ft. (F. H. Snow, 460) ; Wallace Co., Kansas, 3000 ft. 

 (F. H. Snow, 852). Three females, from the same three localities, are 

 numbered 851, 1197, and 445. 



Diadasia sphseralcearum n. sp. 



$. Length 7^ mm. ; like D. diminuta Cr., but with shorter, perfectly 

 white pubescence, and a narrower, more parallel-sided abdomen ; the 

 pubescence of the abdomen, instead of being loose and suberect as in male 

 diminuta, is appressed (except on first segment) and covers the surface ; 

 aside from the pubescence, the hind margins of the segments are them- 

 selves white ; the apex is bidentate, the teeth being like those of diminuta, 

 but rather larger ; hind legs constructed as in diminuta ; shining hairless 

 triangle of metathorax much smaller than in diminuta ; posterior part of 

 mesothorax almost nude ; tegulae subhyaline, ferruginous, dark at base ; 

 antennas entirely black. 



