NORTH OF MEXICO. 



357 



N. gagates, entirely black, sub-opaque. Head densely and finely punctured; margin of epistoma paler. Thorax 

 broader than long", convex, densely and finely punctured, sides feebly rounded, narrowing slightly toward base; apex 

 emarginate, angles distinct; base rounded, angles obtuse. Elytra broad, convex, densely and minutely punctured. 

 Beneath black, shining, sparsely punctured. 



Length .84-. 28 inch. 



This species with the table needs but little description ; it differs from those with 

 broadly oval elytra in its being totally black, thorax narrower at base, base rounded, apical 

 angles distinct, not obtuse. The elytra, are less rounded on the sides, the humeri distinct. 

 There are no elytra! stria; and the punctures are very minute and irregularly placed. The 

 anterior tibia' also, are narrow, not broad, as in the two preceding species. 



Occurs in moderate abundance; at Camp Grant, under stones, and when recent is 

 pruinose. 



N. opacus, Lee, New Species, p. 118. 



The thorax is less transverse than in the broad species which precede, is more convex 

 and is also narrower at base and narrower than the base; of the elytra. The elytra an; 

 elongate oval, rounded on the sides, with distinct humeral angles, surface striate, stria; 

 punctured, intervals feebly convex and finely punctured. The head and thorax are very 

 densely and continently punctured with elongate punctures. 



Length .'20-24 inch. 



The measurement given by Leconte (loc. cit.) is probably a mistake, as his type is 

 one-half longer at least than indicated (.12 inch). 



The anterior tibise are here also similar in the sexes, and are very gradually wider 

 from the base toward the apex. 



Occurs in Arizona and Lower California. 



N. grauulatus, Lee, Ann. Lye. V., 145. 



While similar in form to opacus, this species lias the thorax broader and less narrowed 

 behind, the surface is densely and coarsely punctured. The elytra are deeply striate, the 

 stria 1 closely punctured, the interstices convex and muricatcly punctured. The anterior 

 tibia- of the males serve to distinguish this species from any other. From the bast; to tin; 

 middle these tibia.; are very gradually wider, below flu- middle the tibiee are suddenly ar- 

 cuate, causing them to appear toothed. The tibiee of the female are gradually expanded 

 toward flu; apex and are broader than the male. 



Length .18-.25 inch. 



Occurs at Tort Yuma and Arizona. 



N. sulcatus, Lee, Ann. Lye. V., 145. 



The thorax is sub-quadrate, not narrower behind, sides feebly rounded, almost parallel 

 behind the middle. The elytra are elongate oval, sub-parallel, deeply striate 1 , stria' coarsely 



AMER.I. 1'tlILOSO. SOC VOL. XIV. — 90 



