AIMERICAN COLEOPTERA. 165 



1. M. suturalis. — Slender, cylindrical, blackish-brown, antennae yellow, 

 scape broadly triangular, flattened, fringed towards the tip with very long 

 yellow hairs; head concave; prothorax one-half longer than wide, sides pa- 

 rallel behind the middle, rounded in front, base feebly rounded j surface dull 

 with fine reticulations, and scattered granules gradually becoming larger and 

 acute in front of the middle, where color becomes reddish brown. Elytra with 

 close rows of fine punctures, connected by feeble transverse rugosities, pubes- 

 cence fine and short; posterior declivity convex, sutural angle prolonged into 

 a short acute point. Long. 2*5 mm. 



Illinois ; four specimens sent me by Dr. Henry Shimer, as found on 

 the prickly asli, into the wood of which it bores. This species differs 

 from the next by its more -sleijder form, finer pubescence, and less 

 coarse elytral punctures. 



2. M. aculeatus. — Slender; cylindrical, dark-brown, not shining, elytra and 

 front jjart of thorax paler, antennce yellow, scape triangular, fringed with long 

 yellow coarse hairs, head flat, thinly fringed with long hairs; prothorax a little 

 longer than wide, gradually narrowed and rounded on the sides from the base, 

 which is feebly rounded, surface coarsely granulate, the granules becoming 

 more acute in front of the middle; elytra with transverse punctures densely 

 arranged in rows, and almost connected by intervening rugosities, intervals 

 narrow, with the hairs arranged in lines, appearing like short bristles, po.sterior 

 declivity slightly convex, not at all excavated or toothed, sutural angle pro- 

 longed into a short acute point. Long. 2-5 mm. 



Southern States. Resembles in form the European T. microgra- 

 pJius, but differs generically by the structure of the antennal club. 

 The scape of the antennae is less broadly dilated than in the pre- 

 ceding species. 



SCOLYTUS Geoff-roy. 



The species in my collection may be grouped as follows : 



Venter deeply excavated and armed with long spines 1. quadrispinosus. 



Venter flat or slightly concave: 

 Elytral strise well marked : 



Punctures of intervals very small, without hair: 



Venter coarsely punctured 2. fagi. 



Venter finely punctured 3. califomicus. 



Punctures of intervals bearing short hairs 4. caryse. 



Elytral striae composed of more distant punctures : 



Elytra thinly clothed with very long hair , 5. muticus. 



Elytra glabrous, or nearly so : 



2d ventral segment not tuberculate G. sulcatus. 



2d ventral segment wTth a small apical tubercle 7. ventralis. 



1. S. quadrispinosus Say, Journ. Acad. Nat. Sc. iii, 323. 



Southern and Western States; rare. The specimen in my collec- 

 tion is altogether black, with the exception of the antennae, which are 

 rufous, 



TRAXS. AMER. ENT. SOC. (22) SEPTEMBER, 1868. 



