MORGAN HEBARD 203 



Tliough normally much the largest species of Arenivaga, males 

 are separated with greatest certainty by examination of the 

 concealed genitalia, since some of the males before us from Browns- 

 ville, Texas^ are even slightly smaller than the males of grata 

 here described. 



The female sex is readily recognized l)y its suborbicular form, 

 large size and blackish general coloration. In this sex the inter- 

 ocular space is very slightly narrower than that between the ocelli. 



The species is found through central Texas from near the 

 northern l)ortler to Brownsville. Its distribution is therefore 

 practically co-exteneive with that of tonkoiva here described. 

 The latter, being a smaller paler species in l;)oth sexes, closely 

 related to erratica Rehn, is readily separated in Iwth sexes from 

 hoUiana. 



Arenivaga rehni Hcbanl (Plato VII. figure 2) 

 1917. Arcnimgn rehni Hebard, Mem. Am. Ent. Soc, 2, p. 227, pi. ix, figs. 6 



to 10. [cf , 9 ; San Pedro, Sierra El Tosti, Comondu, San Jose del Cabo, 



all Lower California, Mexico.'] 



From careful examination of the series, we are satisfied that 

 the only mstei-ial which can l)e referred definitely to this species 

 is that from Lower California. As our original descriptions of 

 l)oth sexes and all the figures given are from material from that 

 region, we have little further to add at the present time. We 

 would note, however, that; though variable, the present species 

 by no means shows the very great extremes of variation which 

 we supposed existed, when we believed that other Mexican speci- 

 mens also represented this species. 

 Arenivaga grata new species (Plate VII, figures 3 and 4) 

 1917. Arenivaga rehni Hebard, (in part), Mem. Am. Ent. Soc, 2, p. 227. 



[cf. 9 ; San Lorenzo, Coahuila, Mexico; Kits Peak Rincon, Baboquivari 



Mountains, Arizona.] 



The present species, with bolliana and rehni, forms the first 

 group of the genus, which we term the Bolliana Group. The 

 species in this group agree in the type of the concealed sinistral 

 male genital hook, which is sharply recurved distad near its 

 acute apex, not barl^ed as in the other species. 



3 The material recorded at that time from Arizona and Coahuila is referred 

 in the present paper to A. grata here described, while that from Morelos 

 and Guerrero we can not determine with certainty, as stated on page 198. 



TK.\NS. AM. ENT. SOC, XLVI. 



