NORTH AMERICAN COLEOPTERA. 47 



Thorax a trifle wider at its greatest width thau loug and but sliglitly narrower 

 at apex thau at base ; sides rounded, indented, in a varying degree, at tbe middle 

 and transversely impressed near the apex, latter feebly constricted ; convex and 

 densely scaly, with scattered, erect, but rather short setse ; a narrow median 

 vitta and sides enclosing a darker spot, paler ; lobes rather prominent. Elytra 

 almost oue-lialf wider thau the thorax, same form as in hlrtelUts, scarcely emar- 

 ginate at base ; strise and punctures same as in that species, with the setse a trifle 

 longer and more slender, all erect. Beneath, pectus scarcely punctured and 

 covered with dirty grayish scales. Abdomen less coarsely punctured, each punc- 

 ture bearing a short hair; subglabrous. Legs pale rufous, slender; tarsi long 

 and slender, anterior ones of % with third joint dilated. Leugth 4-4.5 mm.; 

 .16-.17 inch. 



S . Last ventral segment with discal impression. 



9 . Last ventral segnient with large, quadrilateral concavity ; 

 emai'ginate. 



Very similar to the preceding species ; the lateral thoracic inden- 

 tation varies from almost obsolete to a distinct impression, causing 

 the sides of the thorax to appear eraai-ginate ; the color also varies 

 from a uniform grayish white to a yellowish brown with distinct 

 thoracic vittse and the elytra mottled with paler spots. 



Hab. — Texas, District Columbia, Michigan, Northern Illinois, 

 Massachusetts, Arizona, Colorado. 



M. obteetiis n. sp. — Oblong, stouter thau hirtelhis : reddish brown, densely 

 covered above with small, uniformly dirty brown scales, apparently matted to- 

 gether by some animal glue and completely concealing the sculpture. Eostrum 

 stout, shorter than the thorax, as wide at the base as at the apex ; median carina 

 distinct, lateral ones obsolete, sides rounded ; surface finely punctured, thinly 

 clothed with very small filiform scales and a few very short, erect hairs; there 

 is a very faiut indication of a transverse basal furrow. Head broad, very convex, 

 finely punctulate and thinly covered with very small, filiform scales without 

 trace of erect hairs. Thorax as long as wide, base and apex of equal width ; 

 sides straight and slightly diverging for three-fourths their leugth, thence nar- 

 rowed to tip, latter not constricted, but transversely impressed ; surface finely 

 and densely punctured, puuctures concealed by the scaly vestiture, latter inter- 

 mixed with very short, erect, scale-like hairs, prothoracic lobes feeble. Elytra 

 like in the preceding species, but distinctly emarginate at base ; strife and puuc- 

 tures concealed by the scales ; interstices with a row of stout setae. Underneath, 

 legs and tarsi as in hirtellus. Length 3.75 mm. ; .15 inch. 



S . Last ventral with transverse discal elevation. 



Hab. — Arizona. A unique specimen in Dr. Horn's collection. 



HUMILIS Group. 



The species belonging to this group are at once recognized by the 

 fine pubescence with which they are more or less clothed above. This 

 pubescence varies from fine, hair-like to distinctly squamiform. Li 



