TRIBE IV. COSSOXIXI. 520 



tate. Thorax slightly longer than wide, feebly constricted near apex; sides 

 subparallel, very slightly curved; apex broadly, feebly curved, but slightly 

 narrower than base; punctures rather fine but deep, perforate, somewhat 

 sparse, median line obsolete. Elytra twice as long as wide, sides straight 

 and parallel to apical third, then rounded to the obtuse apex; disc with 

 unimpressed rows of large, deep, oblong punctures; intervals flat, narrow, 

 each with a single uneven row of minute punctures. Under surface through- 

 out rather finely, deeply, somewhat densely punctate. Length 2.3 2.8 mm. 



Mt. Washington, X. H., beneath spruce bark. (Blanchard.) 

 Sault Ste Marie, Out.; July 21. Little Codroy River and Nich- 

 olsville, on Hnmber River, Newfoundland. (Bolster.} Described 

 from Minnesota. 



IV. COSSONUS Clairville, 1798. 



Black or piceons species of moderate size, living- beneath the 

 bark of dead trees, and having the body depressed ; beak dilated 

 at tip (Fig. 5) ; antenna^ inserted near the tip, their grooves 

 rapidly descending. An interesting fact in connection with their 

 biology is the frequent occurrence with them of species of the 

 genus Rliyncolus. They have recently been revised by Dr. Edwin 

 C. Van Dyke, loc. cit. Six of the 15 species recognized by him 

 occur in the Eastern States. 



KEY TO EASTERN SPECIES OF COSSONUS. 



a. Black, with base of elytra, metasternum and abdomen rufous. 



828. HAMILTONI. 

 aa. Unicolored black or piceous species. 



b. Thorax as wide or wider than long, sides usually distinctly curved, 

 surface very unevenly punctured; elytral intervals flat. 



829. PLATALEA. 



bb. Thorax longer than wide, sides slightly curved or straight. 



c. Basal portion of beak longer than dilated portion; elytral inter- 

 vals feebly convex. 830. SUBAREATUS. 

 cc. Basal portion of beak equal in length to the dilated portion. 



d. Beak elongate, apical portion distinctly wider than basal and 



rather suddenly dilated. 



e. Thorax somewhat wedge-shaped, almost as wide at base as 

 elytra, sides gradually convergent forwards from in front 

 of base, disc concave on basal third, the impression with a 

 median carina. 831. IMPRESSUS. 



ee. Thorax not wedge-shaped, its sides almost parallel, disc con- 

 vex, coarsely and closely punctured, the median line concave 

 near base: intervals strongly convex. 832. CONCINNUS. 

 (Id. Beak broad and short, apical portion more gradually dilated 

 and but little wider than basal; thorax as wide or wider than 

 elytra. 833. CORTICOLA. 



