38 AMERICAN COLEOPTERA. 



The form of the elytral humeri, whether subangulate or rounded, 

 is a character of considerable importance. 



The elytral striae, whether entire or effaced at tip or nearly obso- 

 lete, have been of service, when properly subordinated to other 

 characters. The eighth stria (counting the sutural as the first), 

 whether or not distinct from the margin, has also been of use in the 

 definition of groups. 



The species themselves are often quite difficult to define, especially 

 in groups v, vii, ix, xii and xvii. Moderately large series of all but 

 our rarest species, amounting in some instances to several hundred 

 specimens, have been studied. No new sjDecies have been described 

 from uniques, although there are several in my own and other col- 

 lections which cannot be satisfactorily placed. Less harnj I believe 

 will be done, however, by postponing the description of a few doubtful 

 species than by increasing our already too large list of synonyms. 

 In reference to this subject I cannot do better than to quote the fol- 

 lowing passage from Dr. Horn's recent paper on Heterocerus^ : " The 

 more specimens examined the greater the difficulty in defining the 

 species and the greater the necessity for the use of judgment in 

 placing specimens." This is equally applicable to Bemhiclium. 



With these preliminary remarks we may divide the genus into the 

 following groups : 



Eyes small, flattened 11. 



Eyes large, or moderately large, convex 2. 



2. Elytra with the humeri subangulate, third interval with dorsal punctures, 



eighth stria distinct from the margin 3. 



Elytra with the dorsal punctures on the third stria 4. 



Elytra with the humeri rounded, third interval with dorsal punctures ... -6. 



3. Mentum with a short, bifid tooth ; strife of elytra more or less abbreviated 



behind. 



Elytral intervals with irregular rows of sparsely placed setigerous punc- 

 tures Group i. Isevig-atum. 



Elytra with two dorsal punctures on the third interval -Group ii. nitidum. 

 Mentum with a large, entire tooth : striie of elytra entire. 



Elytra with two impressed quadrate fovege on the third interval, each en- 

 closing a dorsal puncture Group iii. littorale. 



Elytra without trace of fovefe ; dorsal punctures two. Group iv. coxendix. 



4. Eighth stria of elytra indistinct from the margin, humeri rounded 5. 



Eighth stria of the elytra moderately near, but distinct from the margin, 



dorsal punctures two. 



Hu7neri of elytra subangulate, the strise entire Group v. honestum. 



Humeri of elytra rounded Group vi. concolor. 



* Trans. Am. Ent. Soc. xvii. p. 16. 



