Jg PROCEEDINGS OF THE NATIONAL, MUSEUM vol.71 



nistera oligophylla — O. A. Stevens); Montana; Alberta (Medicine 

 Hat, August 20, 1916; July 17, 1917; Lethbridge, August 18, 1922; 

 August 6, 1923; September 15, 1924; Brooks, July 27, 1923; August 

 12, 1924); British Columbia (Okanogan, July 19, 1915); "N. W. T."; 

 California (Santa Rosa Island and unnamed places) ; Mexico. 



This insect appears to be most common in arid areas, though 

 extending out of them in Texas and California where the female 

 may have the last abdominal segments black. 



One case of abnormal venation has been observed in the specimens 

 studied. This consisted of an incomplete second transverse cubital 

 vein in the fore wing of one side. 



Types. — P. valida (Cresson) was described from two female speci- 

 mens, one of which, now marked Type No. 1929, is in the collection 

 of the American Entomological Society. The type of grossa Cresson, 

 also a female, collected by Heiligbrodt, was supposed to be in the 

 United States National Museum, but the specimen there, marked Type 

 1682, bears the label "Texas. Belfrage." It agrees with the descrip- 

 tion, however, and the label last mentioned probably does not be- 

 long on this specimen. The type of montana (Cameron) is not in the 

 British Museum labelled type, but there is a male specimen there bear- 

 ing this name in Cameron's writing, with the genitalia removed, and as 

 the genitalia of montana were figured by Cameron and the locality, etc., 

 agree, I think there is no doubt this specimen is really the type. There 

 are two specimens oijason in the British Museum, one labelled in Cam- 

 eron's hand and also with a type label. This species will probably 

 prove to be a synonym of valida, different slightly because of its 

 much more southern habitat, but it seems wise to place it here with a 

 sHght doubt. The male grossa of Melander and Brues was described 

 from two specimens taken in Texas, one of which is now in the 

 collection of Prof. A. L. Melander; the location of the other I do not 

 know. 



P. valida male, described by Carter, is now in the collection of the 

 Canadian National Museum. I have seen all of these types with 

 the exception of those described by Melander and Brues. 



There has been some confusion about this species, caused by the 

 idea of early workers that color distribution could be depended on 

 for specific distinction. The first valida had its abdomen entirely 

 jferruginous. In grossa the tip was black and as both were females 

 they were consideredd ifferent species. The males of grossa described 

 by Melander and Brues have black on the abdomen, corresponding 

 with Cresson's female grossa. Carter's valida male is the same and 

 he was perhaps not aware of Melander and Brues' work or thought 

 that, finding no females in Alberta with black on the abdomen, this 

 male could not be grossa but must be the male of valida — in which 

 he was of course correct. 



