JAMES A. G. REHN 247 



colonies. At Sierra Blanca the species was also taken on bare 

 adobe, while on the rocky hills at the same place its relative 

 Mestobregma plattei corrugata occurred. 



The species shows a distinct tendency toward Trepidulus, but 

 it is clearly a Mestobregma. It shows, however, the probable line 

 of relationship of the two genera. A species of Trepidulus shows 

 an approximately similar tendency toward Mestobregma, but the 

 gap between the two remains sufficient to indicate the generic 

 affinities of the respective species. 



The Genus Psinidia Stal 



This genus is composed of two quite distinct species, P. ampli- 

 cornus Caudell and P. fenestralis (Serville). The former was 

 described as a variety, but is very distinct and its distribution 

 within the United States can now be indicated with considerable 

 exactness. The second species, fenestralis, is divisible into two 

 geographic races; one, the tj^pical form, distributed over a verj' 

 extensive area, and the other, which was undescribed, restricted 

 as far as known, to the coastal region of Texas, occurring at the 

 same localities as the very different amplicornus. 



Typical fetiestralis ranges from the most northern points of the 

 species distribution south, in suitable environments, to southern 

 Florida and southwest to at least southern Alal^ama (Flomaton) 

 and the coastal islands of Mississippi (Cat and Ship Islands). 

 Material from Hearne, Robertson County, Texas, is essentially 

 intermediate between the two races. 



Psinidia fenestralis frater new subspecies (Plate XXVII, figs. 10, 17 and 

 IS; plate XXVIII. figs. 18 and 19.) 



This geographic race can be distinguishc'd from typical fenes- 

 tralis (see plate XXVII, figs. 19, 20 and 21) by its greater size, 

 by having the antennae broader and more ensiform in the proxi- 

 mal two-thirds, by the more declivent fastigium and more evident 

 elevation of the vertex, by the head being more compressed when 

 seen in cephalic aspect, by ihc median carina of the pronotum 

 being slightly lower and not as straight in profile, the ventro- 

 caudal angle of the lateral lobes of the pronotum more distinct 

 and peg-like, the distal extremity of the tegima more truncate 

 and less rounded and the jaws of the ovipositor of the female 

 more elongate, more slender and straigliter in profile. 



TRANS. AM. ENT. SOC, XLV. 



