112 GEORGE n. HORN, M. D. 



The followinpj table will enable our species to be recognised : 



Pygidium entirely covered by the elytra in Ijoth sexes. 

 Base prothorax with distinct entire marginal line. 

 Thorax with moderately rounded sides, not broader in front 



than the elytra pinguis. 



Thorax with strongly rounded sides, broader in front than 



elytra validus, u. sp. 



Base of prothorax with marginal line interrupted at middle, 

 sometimes entirely wanting. 



Strife of elytra deep, insterpaces convex hamatus. 



Striae of elytra faint, interspaces fiat. 



Frontal margin broadly rounded, feebly emarginate at 



middle hyperhoreus. 



Frontal margin feebly emarginate at middle and sinuate 



on each side near the angles torpidus, n. sp. 



Pygidium exposed, elytra sub-truncate at tip in both sexes. 

 Thorax with basal marginal line distinct at sides; angles of 



gente obtuse, not prominent occidentalis, vf.^p. 



A. pinguis, Hald., Journ. Acad. Ser. ii, vol. 1, 18J8, p. 10.3. 

 Oblong black, shining, moderately convex. Front broadly rounded, feebly 

 truncate at middle. Head finely punctured, coarser and more dense on front 

 and toward the sides, finer and more sparsely placed on the vertex. Thorax 

 broader than long, feebly narrower behind and not broader than the elytra; 

 sides and base with distinct marsiinal line; sides (when viewed from above) 

 feebly rounded ; disc shining, moderately convex and with large punctures 

 very distantly placed at the sides and toward the base, between which are fine 

 punctures evenly scattered over the entire surface ; elytra about one-half 

 longer than thoiax, slightly depressed, sides moderately rounded with moder- 

 ately impressed stricB, not coarsely nor closely punctured, interstices flat, very 

 finely and sparsely punctured. Beneath coarsely and distantly punctured. 

 Legs brownish ferruginous, antennse paler. Length .30 inch; 7.5 mm. 



Male. — Spur of anterior tibiae broadly spatulate, inner spur of middle tibice 

 short robust and unconspicuous. First joint of hind tarsus V-shaped. 



Female. — Spur of anterior tibiae acute but strong, inner spur of middle tibiae 

 slender, at least half the length of the outer. Hind tarsi normal. 



Tn both sexes the anterior tibiae have the outer edge above the 

 upper tooth simple, not serrate. 



Occurs in the Lake Superior region. 

 A. validus, n. sp. 



Resembles j9i«(/«t.s but diifers in the following characters: — Sides 

 of thorax very broadly rounded, and broader than the elytra. Elytra . 



comparatively shorter than in pinguis and scarcely one fourth longer, jf^^.r'-l/i^f 



This species has a much more robust facies than pinguis. The 

 thorax is more convex and shining and with fewer large punctures at 

 the sides and scarcely any at the base. The legs are more robust and 

 the first hind tarsal joint of male is more strongly developed than in 

 any of the species of the group. The color of the upper surface is 



