10 Le Conte on the Pselaphide of the United States. 
The first group (with the front elevated,) is the normal 
form, and shows an unbroken series; Metopias, with its im- 
marginate abdomen, being the inosculating point with Batri- 
sus ; which by slight variations in the form of its front, shows 
its tendency towards the typical stem. 
The second group requires more careful analysis. The 
curious sculpture on the thorax of many of its members is not 
found in the first group, and should lead us to suspect that it 
may be the connecting chain with other forms. The embry- 
onic character is plainly seen in the elongate form, and six- 
articulated abdomen of Euplectus ; while in the other series, 
Adranes, though of very low organization, preserves the typ- 
ical Pselaphus form. Of the two genera in this second series, 
Hamotus is plainly a Bryaxis form, while Faronus is a Euplec- 
tus form. Accordingly the genera must be thus arranged. 
Scydmenoid genera. Oxyteloid genera. 
Hamotus. Batrisus. 
ryaxis. 
Eupsenius. Rhexius. 
Arthmius vs 
Bythinus 
B A. 
Euplectus. 
Faronus. 
The left hand branch being almost typical Pselaphi, with 
globular thoraces, scarcely sculptured, and leading very ob- 
viously to the Scydmeni; the right-hand branch being alto- 
gether abnormal, Batrisus being the only genus tending at all 
to the typical chain. The six-jointed abdomen and elongate 
form of Euplectus, proves that the lower forms of this liné 
must possess a multiarticulate abdomen, with a linear body. 
They must therefore be sought for among the Brachelytré. 
Now the three-jointed tarsi, (which must of course be pre- 
served through the lower forms,) occur only in Erichson's 
division Staphylini Oxytelini, where we also find sculptured 
thoraces agreeing with those of our Pselaphide. ; 
