180 J. L. LECONTE, M. D. 



4. — Elytra dark with broad apical yellow margin; 3.4 inin.; Middle and South- 

 ern States, (linearis Ev .) 3. binotatllS iSay. 



a. — Elytra dark with narrow sutural and apical margin reddish. 

 ,J. — Yellow-brown, head, elytral marginal spot, and sometimes the tip of 

 abdomen dark; hinotatus Say 

 5. — Elytra shorter than prothorax, head dark; 3.4 mm.; Mass.; Mich. 



4. brevipennis Austin. 



Elytra longer than prothorax, head pale; 3 — 4.2 mm.: Atlantic and Paci6c 



regions 5. lougiusculus Mann. 



>S. monstrosus Lee, belongs to Stilicopsis. 



I am unable to separate S. similis Austin, and S. frisijnatus Boh., 

 from S. Jougiusculus. 



S. centralis Austin, is a pale form of race /3, of species 3. hinotatus, 

 of which S. linearis Er., is the darkest form. 



In all of these species the sixth ventral segment of the % has a 

 small triangular emargination at the middle. 



OXYPORUS Grav. 



At the time I published the synoptic table of the species of this 

 genus,* I had not recognized any sexual characters. 



Last year my attention was called by my friend and excellent 

 observer, Mr. Frederick Blanchard of Lowell, Mass., to some re- 

 markable differences he had noticed in the mandibles of several 

 species, and to hairy patches seen on the fifth ventral segment of very 

 well preserved % 's of 0. lateralis and occipitalis. 



In 0. lateralis the left mandible of the % has a tooth just behind 

 the apex, which is wanting in occipitalis ; aud in the former the patch 

 of soft silky hair extends two-thirds the length of the fifth ventral 

 segment forward from the hind margin, while in the latter it is 

 less developed. 



The tooth of the left mandible of both sexes, which in most of the 

 species supports in repose the inner edge of the right mandible, is 

 smaller in these two species than in the others, in which, moreover, 

 both Mr. Blanchard and myself have failed to discover any sexual 

 differences, except those indicated by the larger head and less rounded 

 sides of the prothorax of the males. 



In 0. b-maculatus the tooth of the left mandible is nearer the 

 base, and is reduced to a very small cusp on the inner edge, and in 

 0. lepidus it is entirely wanting. 



« Trans. Am. Ent. Soc. 1877, 214. 



