326 BRENTHID^. [LeConte. 



black, the red and the post oaks are mentioned as those which are known 

 to be attacked. By some curious inadvertence, Olivier in the Encyclopedic 

 Methodique cites for this species No. 84, plate ii, f. 9; a totally distinct spe- 

 cies, which in the text (v, 439) is named B. militaris. 



A description of this very well known insect is here unnecessary, but a 

 notice of the variations Avhich I have observed in the head of the males 

 may be of interest. 



The females vary in length from 6.5 to 14 mm.; .25 to .56 inch., from 

 the eyes to the tip of the elytra. The head is rather strongly constricted 

 immediately behind the eyes, which are convex and prominent. Imme- 

 diately in front of each eye is a deep fovea; and in advance of them is a 

 deep frontal excavation; the ridges above the insertion of the antennae are 

 prominent, and not angulated; the beak in front of the antennas is as long 

 as the joints 1-9 of the antennae, which are shorterand stouter than in the (^. 



The males vary in length from 7.2 to 17 mm.; .28-67 inch, from the 

 eyes to the tip of the elj^tra. The head affects three different forms, which 

 seem to be independent of size : 



1. The head is suddenly, but not strongly constricted behind the eyes, 

 with the lateral angles obtuse, but distinctly outlined; the ridges above the 

 antennae are very prominent, angulated behind, and separated from the 

 front by ti deep impression; the frontal impression is large and deep, and 

 the median elevation in it is feeble; the beak in front of the anteunaj is 

 strongly dilated, much wider than long, with scattered elevated granules, 

 and with a well developed ridge each side, which is suddenly more elevated 

 at its posterior end; there are also two shallow impressions. The mandi- 

 bles are as long as the beak in front cjf the antennae; the cusp on the inner 

 side is distinct and the apex of the right mandible has three cusps, that of 

 the right but two. This form occurs in Michigan and Georgia. 



2. The beak in front of tlie antennas is not transverse, but fully as wide 

 as long; the other characters as in (1). This form occurs in Kansas and 

 Texas. 



3. The beak in front of the antennae is nearly twice as long as wide, the 

 lateral ridges less developed, the granulations more numerous, the mandi- 

 bles comparatively shorter and stouter; the frontal impression more elon- 

 gated, with the median elevation more distinct; the ridges above the inser- 

 tion of the antennae are less prominent, not angulated behind, and the head 

 is less suddenly constricted behind the eyes, with the angles so much 

 rounded as to be nearly effaced. 



These characters are somewhat similar, as regards the development of 

 the supra-antennal ridges to those observed in Lucanidce, but in the varia- 

 tion of the length of the beak are rather anomalous. They indicate, how- 

 ever, the propriety of recasting the classification of this family, and defining 

 the genera and species by the invariable characters of the female, rather 

 than by the perhaps individual modifications of the male. 



The measurements given above show a slight average superiority of size 

 in the male, but not sufficient to warrant any generalization in favor of 



