MICROBORUS.—PYCNARTHRUM. 175 
MICROBORWUS, gen. nov. 
Caput exsertum, parum rostratum. Oculi permagni, supra et infra approximati, grosse granulati. Antenne 
breves, clava depressa, subtunicata, apice oblique truncato, suturis concentricis notato. Prothorax 
subcylindricus, lateraliter sinuatus, inde medio quasi subangustatus. Tarsorum articuli 3 primi breves, 
sequales. 
Head free, indistinctly rostrate. Eyes very large, formed each of five rows of very coarse granules, approximate 
above and below the head, the inferior interocular space the narrower. Antenne very short, the scape 
curved, joints 2-6 of the funiculus not increasing in width; club orbicular, somewhat flattened obliquely, 
the sutures extending more towards the apex on the inner than on the outer face, so that the club viewed 
from the side appears to be subtunicate, and approaches that of Xyleborus. Prothorax slightly constricted 
about the middle, the sides therefore appearing sinuate, their margins weak. Anterior coxe remote from 
each other and from the front prosternal border. Tibie not strongly dilated, their upper border serrate ; 
the anterior pair obliquely excised at the apex and uncinate at the inferior angle. The three basal tarsal 
joints short, equal and simple. 
This genus is established for a single curious little species which resembles a 
Crypturgus. Its position must, to some extent, be regarded as doubtful, for but one 
example has reached us, and it is difficult to make out structural details in so small an 
insect. The structure of the antennal club separates it from the remaining genera of 
the group; although it has been as carefully examined as circumstances permit, it can 
only be fully elucidated after mounting in balsam. 
1. Microborus boops, sp.n. (Tab. VII. fig. 1.) 
longatus, subdepressus, ferrugineo-testaceus, capite et prothoracis disco nigricantibus; prothorace oblongo, 
punctato, linea media levi; elytris punctato-striatis, striis postice profundioribus, interstitiis convexis in 
declivitate breviter seriatim sctosis. 
Long. 1°6 millim. 
Elongate, rather depressed, reddish-testaceous, the head and dorsum of the prothorax (except the anterior and 
posterior borders) blackish. Head finely reticulate, sparingly punctured and pubescent; mouth reddish, 
fringed ; antenne testaceous-yellow. Prothorax a third longer than broad, the hind angles rounded and 
margined, the sides sinuate, the apical margin rounded; surface glabrous, gently convex from base to 
apex, very finely reticulate, and with distinct punctures sparse towards the middle of the sides and absent 
over the median line. Scutellum small, rounded, and not impressed. Elytra a little wider than the 
prothorax and one-half longer, truncate at the base with the shoulders rounded-rectangular, parallel- 
sided, subcircularly rounded at the apex; surface subcylindrical to the hinder third, thence convex, 
punctate-striate, the strie rather shallow at the base, deeper behind, the interstices somewhat convex, 
delicately rugulose, with single rows of minute punctures, carrying short sete on the declivity. Under- 
side and legs reddish-testaceous ; the former thinly pubescent. 
Hab. Guaremata, Tamahu in Vera Paz (Champion). 
One example. The large size and extremely coarse granulation of the eyes are quite 
without parallel in the smaller species of Scolytide. 
PYCNARTHRUM. 
Nemobius, Chapuis, Syn. Scol. p. 41 (1869) (Mém. Soc. Liége, 1873, p. 249) (nomen preocc.). 
Pycnarthrum, Hichhoff, Rat. Tom. p. 104 (1878). 
In Pycnarthrum the head is feebly rostrate and but little covered by the front of the 
