386 CLASSIFICATION OF THE CARABIDiE 



yet undescribed, but as isolated descriptions would tend only still more to confuse this 

 difficult genus, they must be made known at some future time in the form of a synopsis. 

 Our species form four groups: 



1. The first contains those species which have the posterior angles of the thorax rounded, and the 

 anterior and middle tarsi of the male broadly dilated, the fourth joint being deeply bilobed : the de- 

 scribed species are, carbonarius Brulle, (Harpalus carb. Dej. ;) sprctus Dej. ; fuliginosus Dej. 

 (versicolor Kirby, and fuscipennis Lee. ;) plebeius Dej. ; fuscatus Dej. and coniunctus Lee. 

 (Trechus coniunctus Say, Acupalpus misellus Dej.; Ac. rotundicollis et lugubris Hald.) 



2. In this group the posterior angles of the thorax are rectangular and prominent; the tarsi of 

 the male as in the first group; the alternate spaces of the elytra are marked with indistinct series 

 of punctures: only one species belongs here, S. alternans Lee. (Badister testaceus Lee. Proc. 

 Acad. Nat. Sc. 2, 252, Aepus testaceus ejusd. Ann. Lye. 4, 413.) The name testaceus, being pre-oc- 

 cupied by Dejean's Acupalpus testaceus entering this genus, must be changed. 



3. This contains several species like S. ochropezus Say (of which S. eonvexicollis Lee. is a va- 

 riety) in which the posterior angles of the thorax are rounded and the middle tarsi of the males 

 scarcely dilated : here belong S. d i s s i m i 1 i s and unicolor Dej. 



4. The fourth group consists of very small species, having the male tarsi imperfectly, or not at all 

 dilated: the form of the thorax is variable, although the posterior angles are never very prominent. 

 Here belong all the species of Acupalpus, mentioned in the fourth volume of the Annals of the 

 Lyceum, except A. suturalis, which, as above stated, is a Bradyccllus. A. micfos Lee. is not suffi- 

 ciently distinct from A. testaceus Dej. 



Trechicus Zim. 

 This genus is proposed to me by my friend Zimmerman, on two small insects from the 

 Southern States, which have very much the appearance of minute Trechus, both by the 

 form of the body and by the elongate acuminate palpi : the males have four joints of the 

 anterior tarsi slightly dilated: the marginal stria of the elytra is entire, not interrupted as 

 in Trechus: the labrum is square and flat, the mentum not toothed; the antennas are as 

 long as the head and thorax; the 2d and 3d joints equal; the following ones broader and 

 thicker, somewhat moniliate, gradually very slightly increasing in size; the thorax is 

 subtrapezoidal, narrowed behind, with obtuse angles; the elytra are broadly rounded at 

 tip, scarcely striate; the 3d interstice with three impressed punctures; the 8th stria entire, 

 and reaching almost to the suture. The species were first sent me by Zimmerman, under 

 the names that I have adopted. 



1. T. umbripennis, testaceus, nitidus, capite nigricante, ore palpis antennisque rufo-testaceis, 

 elytris obsoletissime striatis, cyaneo-micantibus, thorace vix sesqui latioribus, disco ct apice infuscatis. 

 Long. -11. Georgia and Carolina. 



2. T. pallipennis, piceo-testaceus, nitidus, capite thoraccquc nigris, elytris thorace plus sesqui 

 latioribus, pallidis, striis vix distinctis, sutura apiccquc late subinfuscatis, pedibus, palpis, antennisque 

 pallidis. Long. -09. Carolina. 



EuCERUS Lre. 

 A singular genus which illustrates still farther the affinity towards Trechus, and slightly 

 towards the Lachnophori. The form is altogether that of Trechus, except that the elytra 



