Casey — A Revision of the American Paederini. 105 



to that of Doinene. They are of more or less robust form, 

 of small to moderately large size and are gradually pointed 

 anteriorly, being widest at the elytra, with the prothorax and 

 head decreasing in width, giving them a somewhat fusiform 

 outline. The maxillary palpi are long and notably slender in 

 the present genus, the fourth joint being unusually slender 

 and aciculate, the antennae more or less long, slender and 

 filiform, with the hind tarsi as in Lathrobium. The elytra 

 are always larger and more closely punctate than in that 

 genus, without trace of linear arrangement. The slender neck 

 is undoubtedly a most significant and conclusive generic char- 

 acter and Tetartopeus should in no wise be considered a sub- 

 genus of Lathrobium. The species are rather numerous and 

 very widely distributed over the holarctic regions of the earth, 

 extending as far south in North America as Florida and 

 Texas, but most abundant in the colder sections of the north- 

 ern continents. Those represented by material in my cabinet 

 may be readily known as follows : — 



Elytra at least as long as the prothorax, aud, in all but very rare cases, de- 

 cidedly longer 2 



Elytra shorter than the prothorax, the body more parallel 16 



2 — Eiytra red or piceous, sometimes clouded with blackish toward base or 



near the suture, never abruptly paler at apex or at the external apical 

 angles 3 



Elytra black or blackish, with the exttrnal apical angles more or less 

 abruptly pale, the pale tint sometimes extending across the apex.... 9 



Elytra intense black throughout; the entire body black, the legs dark — 14 



3 — Prothorax deep black 4 



Prothorax pale testaceous, similar in color to the elytra 8 



4 — Head parallel or only very feebly and gradually narrowed behind the 



eyes and then only in the female 5 



Head very obviously narrowed behind the eyes in both sexes 7 



5 — Prothorax not very coarsely and unusually sparsely punctate. Body 



moderately stout and convex, polished black, the elytra dark piceo- 

 rufous; head parallel at the sides behind the eyes, the base semicircu- 

 larly rounded ; eyes at three-fourths more than their own length from 

 the base, measured on the median line as usual; antennae scarcely as 

 long as the head and prothorax and rather thicker than usual, the me- 

 dial joints about two-thirds longer than wide; prothorax very much 

 wider than the head, oblong, broad, only slightly longer than wide, 

 highly polished, very sparsely and somewhat inconspicuously punctared ; 

 elytra quadrate, parallel, a third wider and about a fourth longer than 

 the prothorax, fully as long as wide, the punctures rather close-set 



