34 GEO. H. HORN, M. D. 



sides slightly sinuate, basal region slightly depressed, a small ante-scutellar carina 

 not quite reaching the middle in front, surface rather coarsely but not densely 

 nor roughly punctate ; elytra indistinctly striate, the punctuation well marked 

 and slightly rugose. Length .18 inch ; 4.5 mm. 



This species is unknown to me, and the above description is from 

 Bonvouloir. It apparently resembles subsinuatus more closely than 

 any other of onr species. It is to be regretted that Bonvouloir has 

 omitted special mention ( f tho supplementary carina? in nearly all 

 his specific descriptions as they seem important, not only in the man- 

 ner he uses them in his synoptic table, but for the se])aration of 

 closely related species. 



One specimen from Illinois (Museum at Stockholm). 



M. triaiigiilaris Say. — Form moderately elongate, narrower behind, pice- 

 ous, or nearly black, feebly shining, very sparsely clothed with short yellow- 

 brown pubescence ; antennae piceous, feebly serrate, extending one-half 9 , or 

 three-fourths the length of body % ; head rather coarsely, closely punctate, a 

 slight depression above the base of the clypeus,_vertex feebly carinate or not ; 

 clyiJeus narrower at base than the distance between it and the eye ; prothorax 

 with the length and width nearly equal, sides straight and parallel, arcuate at 

 the front angles, hind angles carinate ; disc moderately convex, a distinct ante- 

 scutellar carina terminating in a slight median depression ; anterior supplemen- 

 tary carina short, oblique, the posterior long, reaching the middle of the thorax ; 

 juxta-sutural sulcus smooth and deep, nearly parallel, the outer carina entire ; 

 surface of thorax moderately, coarsely and densely punctured ; elytra obsoletely 

 substriate, closely and roughly punctate ; body beneath coarsely and moderately 

 closely punctate ; metasternal episterna nearly concealed in front, slightly wider 

 behind ; hind coxal plates distinctly narrower externally ; legs brownish ; fourth 

 joint of tarsi broader and slightly lobed beneath, tarsal claws dilated at base. 

 Length .12 - .16 inch ; 3 - 4 mm. 



In some specimens the thorax is impressed on each side, otherwise 

 there is no notable variation except in size, and somewhat in color. 

 Occurs from Canada to Georgia. 



M. iini>re»<>!!>icolIis Bonv.— Form elongate, subcylindrical, slightly nar- 

 rower behind, rufo-ferruginous, feebly shining, sparsely clothed with very short 

 fulvous pubescence ; anteunse a little longer than half the body, joints four to ten 

 distinctly serrate ; head coarsely, densely and rather roughly punctured ; clypeus 

 broad at base and nearly twice as wide as the space between it and the eye ; pro- 

 thorax a little wider than long, slightly narrower in front, sides posteriorly j)ar- 

 allel, anteriorly arcuately narrowing, hind angles short, acute and distinctly 

 carinate ; anterior supplementary carina short, slightly arcuate, the posterior 

 very long and almost joining the apical margin; disc convex, a median im- 

 pressed line starting fi-om the base and reaching the middle, where it becomes 

 deeper and broader, surface densely, coarsely and somewhat roughly punctured ; 

 juxta-sutural sulcus moderately deep, but relatively narrow, the outer carina 

 well marked but feebler in its basal extension outwardly ; elytra distinctly striate, 



