1909.] NATURAL SCIENCES OF PHILADELPHIA. 443 



The previous records of the species are all from southeastern and 

 southern Arizona. 



Trepidulus rosaoeus (Scudder). 



At Las Vegas, Nevada, August 10, this species was found numerous 

 in bare desert places, both the typical phase with the wing roseate 

 proximad and one with the same portion hyaline with an extremely 

 faint whitish suffusion being taken. The series numbers twenty- 

 five males and seven females, each phase represented by sixteen indi- 

 viduals. Fourteen males and two females have the wings roseate 

 and eleven males and five females have the same members hyaline. 



There is little variation in size, although the tegmina and wings 

 vary somewhat in length. The degree of production of the ventro- 

 caudal angle of the lateral lobes of the pronotum varies considerably 

 and in a number of specimens the angle is well rounded. The character 

 of this angle cannot be correlated with the color of the wings. The 

 general color is more ashy in some individuals than in others, some- 

 times touched with dull reddish and again with the maculations more 

 decided than in others. The Nevada specimens as a rule are paler than 

 representatives from southeastern Arizona, but they are well matched 

 in individuals from the lower Arizona deserts at Yuma and Florence. 



Derotmema delioatulum Scudder. 



The published records and the material at hand indicate that this 

 species is well distributed over the lower portions of the Mohave 

 desert and a considerable area of the Gila desert. A series of fifty- 

 four Calif ornian and Nevadan specimens is now before us, the following 

 localities being represented: Cottonwood, September 9, two males, 

 two females; Goffs, San Bernardino County, California, September 

 10, one female; Kelso, August 12, five males, seven females; North 

 Range of Providence Mountains, August 12, six males, four females; 

 foothills Bird Spring Mountains, California, August 11, two males, 

 six females; foothills Bird Spring Mountains, Nevada, August 11, 

 ten males, eight females; Arden, Lincoln County, Nevada, August 

 9, one female. When compared with two pairs from Sentinel, Mari- 

 copa County, Arizona, the eyes of all the Californian and Nevadan 

 individuals are seen to be slightly less prominent than in the Sentinel 

 specimens, but in all the essential characters they fully agree. The 

 geographic and individual differences in size are very slight, but the 

 caudal margin of the disk of the pronotum varies from broadly obtuse- 

 angulate to subarcuate. The Kelso and Goffs individuals are paler 

 than the others, in this respect resembling the Sentinel specimens, 



