466 PROCEEDINGS OF THE ACADEMY OF fjune;. 



marbled with a darker shade, lateral lobes heavily marked with very 

 dark bistre. Tegmina mummy brown marked cephalad with dark 

 bistre. Ovipositor burnt umber. Limbs and ventral surface of 

 body wood brown tinged with russet, the longitudinal markings on 

 the outer surface of the caudal femora very faintly indicated. Inter- 

 mediates between this and the normal Texan type are to be found in 

 specimens from San Jose del Cabo, L. Cal., Las Vegas, Nev., and 

 Brownsville, Tex. 



The typical series from St. George, Utah, all of the Californian 

 specimens except those from Fort Yuma, and almost the entire series 

 from Las Vegas, Nev., belong to a color phase closely resembling 

 that of the specimens from Vera Cruz, excepting that these specimens, 

 are not so much tinged with russet, the usually distinctive cephalic 

 markings are very obscure (practically absent in many cases), while 

 the females have the intermediate channel of the tegmina strikingly 

 cream colored. Intermediates between this type of coloration and 

 that of the Mexican series are at hand, but in none of the Texan 

 series is a close approach to this to be found. In all other respects,. 

 however, the specimens are inseparable and consequently not worthy 

 of even racial distinction. 



Distribution. — The present geographic race is known to range from 

 Biloxi, Miss., to the Pacific coast, and southward as far as the state 

 of Tabasco, Mex. The most northern localities at which it has been 

 taken are St. George, Utah, Las Vegas, Nev., and the Panamint 

 Valley, Cal. 



Biological Notes. — In the desert regions of the southwestern. 

 United States this insect is but very occasionally met with in the 

 short grasses growing near streams and other restricted damp areas, 

 but in the semiarid mesquite region of Texas it is widely distributed 

 in the short grasses which are there so frequently encountered; and 

 its range extends still further eastward, where it is found in the 

 typical undergrowth of the long-leaf pine forests. A few macropter- 

 ous specimens have been taken at light at Beaumont, Brownsville, 

 and Del Rio, Tex. ; other than at light this long-winged form has 

 scarcely ever been encountered. 



Morphological Notes. — It is the opinion of the author that the 

 considerable amount of variation found in the present insect is due 

 to its frequent isolation together with its very extensive distribution. 

 Though ranging over all the desert regions of the southwest, this 

 insect, like all other North American Nemobius, is never found unless 

 a certain amount of moisture is present. In its desert distribution 



