OOLEOPTERA. 459 



CoLOBicus, Lat. 



In this and the following subgenus, the tarsi, from the point where 

 they are moveable, seem to consist of but four joints, of which the 

 three first, much shorter than the last, are entire, and simply furnished 

 underneath with a greater or smaller number of hairs; the first as in 

 several of the Cleri of Fabricius, is only visible underneath, where it 

 forms a little projection; it is also pilose. The palpi of the Colobici 

 and those of the following subgenus are terminated by a joint some- 

 what thicker than the preceding one *. 



In the other Nitidularise, the artennal club always consists of three 

 joints, and the head never projects over the mouth. 



Sometimes the first joint of tlie tarsi, as in the Colobici, is very 

 short, and the three following ones elongated, equal, entire, and 

 simply pilose underneath; the palpi are thickest at the extremity. 

 Such is 



Thymalus, Latr. — Peltis, Fab. — Silpha, Lin. 



In those species where the body is almost hemispherical — limhatus 

 — the antennal club is proportionally shorter, and the third and fol- 

 lowing joints smaller than the second; the tibial spurs are extremely 

 small f. 



Sometimes the three first joints of the tarsi, at least those of the 

 males, are short, wide, and emarginated or bilobate ; the fourth is 

 very small, but slightly or not at all visible ; the maxillary palpi, at 

 least, are filiform. 



Here, the tibitie, at least the anterior ones, are widened at the ex- 

 tremity in the form of a reversed triangle ; the first joint of the an- 

 tennse is usually larger than the second, and the elytra are generally 

 truncated posteriorly, or very obtuse. 



In the two following subgenera, the third joint of the antennae is 

 evidently longer than the following one, and the antennal club abrupt 

 and nearly orbicular or oval. 



Ips, Fab. — NiTiDULA, Oliv. Lat. — Silpha, Lin. 



The body always forming an oblong oval, and depressed ; posterior 

 extremity of the abdomen exposed ; one of the mandibles — the left — 

 truncated and tridentated at the extremity, and the other widened 

 and broadly emarginated or concave at the same end ; terminal lobe 

 of the maxillae elongated |. 



NiTiDULA, Fab. — NiTiDULA, Strongylus, Herbst. — Silpha, Lin. 



The two mandibles become narrowed near the extremity and ter- 

 minate in an emarginated or bifid point. 



Some are flattened, oblong, or ovoid; the others are orbicular and 

 arched or proportionally more convex than the preceding. Thus 



* Lat. Gener. Crust, et fnsect. II, p. 9, and I, xvi, 1, 

 f See Fabricius, Gyllenhal, and Schoenherr. 



X Some of the species of Fabricius should apparantly be referred to his genus 

 Engis. 



