The Pselaphid^ of North America. 47 



eighth equal, transverse, seventh, eighth and ninth gradually 

 wider; ninth as wide as the second, and twice as wide as the 

 third; tenth of the same form larger both ways; eleventh coni- 

 cal-ovate, sHghtly wider and truncate at the base, as long as 

 the two preceding ones. Prothorax widest on the anterior 

 third, as wide as the head, anterior, edge broadly arcuate, 

 transverse, base not quite three times wider than the neck; 

 sides, wath the base, forming a broad arch, nearly semicircular; 

 the sides bear three recurved spines, the disk is depressed- 

 convex, with a Hnear median sulcus crossing a transverse 

 linear one, which ends at the sides in a longitudinal arcuate 

 depression, with a small round fovea. Elytra as wide across 

 the high, spinous, prominent shoulders as the suture is long; in 

 the middle they are slightly broader, sides slightly arcuate, 

 depressed, impunclate, disk narrowly elevated; sutural Hnes 

 straight, well impressed, discal Hnes deep at the basal fovea, 

 evanescent before the middle; from the humeral spine to the 

 tip, near the lateral margin, is a sub-marginal sharp ridge. 

 Abdomen strongly margined, convex, tumid in the middle, first 

 segment depressed at the base with two short carina one- 

 fourth of the total width apart. Legs rather short. ? second 

 tarsal joint dilated, the ventral segments longitudinally con- 

 cave, the last ventral transverse; at the tip is a deep funnel- 

 shaped fovea situated in a lunately depressed area. 



Habitat. East of the Mississippi River from north to 

 south. 



R. suBSTRiATUs, Lcc. Browm, less convex than R. in- 

 sctdpius. 



Head of the same form and sculpture as in the preceding 

 species. Prothorax \\\\.h. a longitudinal hnear sulcus and three 

 large impressions near the base. Elytra with the basal mar- 

 gin elevated (as in P. insctilptus), basal fovea deep, each 

 elytron with four faint striae, of which the sub-sutural one is 

 longer and more distinct, the others extending only about to 

 the middle. Antennee with the ninth and tenth joints less sud- 

 denly larger than in P, inscid^tus. Length 1.2 mm. 



Habitat. Florida. 



