162 RHYNCHOPHORA. 
PHLGOTRIBUS. 
Phloiotribus, Latreille, Préc. car. gén. Ins. p. 50 (1796). 
Phleotribus, Chapuis, Syn. Scol. p. 43 (Mém. Soe. Liége, 1873, p. 251) ; 
1868, p. 148. 
This genus is readily distinguished by the lamelle into which the joints of the 
The species previously described 
Leconte, Tr. Am. Ent, Soc. 
antennal club are produced on their inner side. 
number seventeen, of which all, except four, are American. ‘They differ very much in 
the length of the antennal lamelle, but this character must be employed carefully in 
differentiation, as no abrupt line of demarcation can be drawn between the species with 
long and those with short lamell. 
The males are to be distinguished by the possession of one or more of the following 
characters :—a frontal impression; development into tubercles or blunt spines of the 
ridges forming the anterior boundary of the antennal pits; a pencil of long hairs on 
the scape; and, in those species which have the anterior half of the prothorax tuber- 
culate, a uniform distribution of the granules, which in the females are aggregated 
towards the anterior angles. 
The insertion of the antenne is stated to be frontal; this is apparent in some 
species, but not in those in which the ridges bounding the antennal pits in front form 
the lateral margins of the frontal area. It is, however, true that the point of insertion 
lies constantly above and not on a line connecting the middle of the eye and the side- 
border of the mandible. 
1. Club of antenna not twice as broad as long, its lamelle short, semi- 
crescentic, tapering from base to apex; elytra pilose . . - + + + 2. 
Lamelle of club elongate, parallel-sided ; elytra with seriate bristles or 
subglabrous .. .- 3. 
4. Prothorax with a median smooth line obliquus, Chap. 
Prothorax without trace of amedian line . . . - + + + = sulcifrons, Chap. 
5. Prothorax uniformly granulate or rugose. . . - 6. 
Prothorax with basal half smoother than apical half 3 
6. Elytra black ; interstices convex, very narrow demessus, sp. 0. 
Elytra brown ; interstices flat, less narrow ee asperatus, sp. 0. 
7. Anterior border of prothorax without prominent tubercles 8. 
Anterior border of prothorax with four prominent tubercles . biguttatus, sp. 2. 
8. Elytral setz coarse, pale ; form oblong-oval . 9. 
Elytra thinly covered with short stiff hairs . . . . + + + + 
Elytra with fine decumbent pubescence, interstices with uniseriate hairs. 
Elytral bristles short, scale-like, forming a double row on at least the 
sutural interstice . a 
Elytra without perceptible series of bristles ; form short-oval (length over 
3millim.) 2. 2... 2 6 ee ee es 
Elytral interstices with distinct uniseriate hairs . 
Elytral setz fine, black or fuscous ; form oval 
discrepans, sp. 1. 
nubilus, sp. 0. 
scabratus, sp. 0. 
4. 
5. 
10. 
