BATRISINI 215 



animals (earthworms) and some species may be facultative myrmecophiles, 

 living freely in floor mold and the nest of ants (Park, 1932, 1935b). Many 

 species of neotropical areas come to lights at night, as will be noted later. 



Key to the Neotropical Genera 



Body short, thick and globular (PI. XVIII) 2 



Body elongate-cylindrical (PI. XVIII) 3 



2. Humerus of elytron produced into a distinct callus ; metasternum never 



medianly carinated EUPHALEPSUS (PI. XV, XVIII) 



Humerus of elytron without a callus or swelling ; metasternum always 

 medianly carinated PHALEPSOIDES 



3. Lateral margins of first tergite with both an external and an internal 



carina as the margin of the segment; other tergites with only a single 



lateral carina or no carina (PI. XIX, 1) 4 



Lateral margins of the first three or four tergites with both an ex- 

 ternal and an internal carina (PI. XVIII) BATOCTENUS 



4. Elytron with a well marked dorsal stria ITETICUS 



Elytron with no dorsal stria or replacing dorsal depression 5 



5. Pronotum with a subbasal transverse sulcus, and without antebasal 



spines 6 



Pronotum with no subbasal transverse sulcus, but with two large ante- 

 basal spines, and at times with a smaller spine on each side of the 

 pronotum anterior of middle OXARTHRIUS 



6. Pronotum with the lateral margins entire 7 



Pronotum with each lateral margin distinctly incised or gashed. . . . 



SYRMOCERUS (PI. XIX) 



7. Pronotum with a lateral longitudinal sulcus on each side . . SYRBATUS 

 Pronotum without lateral longitudinal sulci ARTHMIUS 



ARTHMIUS (LeConte, 1850) 



LeConte (1850) (Arthmius) 



LeConte and Horn (1883) {Batrisus) 



ScHAUFuss (1872, 1879) {Batrisus, Bryaxis) 



Raffray (1890) (Batrisus) 



Raffray (1897, 1904, 1908, 1911) (Arthmius) 



Sharp (1887) (Batrisus) 



Fletcher (1928, 1930) (Arthmius) 



In 1850, John L. LeConte erected the genus Arthmius and the genotype, 

 Arthmius globicollis LeConte, for a small batrisine whose range is now known 

 to cover the eastern third of the United States (Florida and Georgia north- 

 wards into Pennsylvania). Few genera were destined to be more important 

 taxonomically. Thirty-three years later LeConte and Horn placed globicollis 

 into Batrisus, since the species had been described as having a single tarsal 

 claw but later study "with a powerful microscope" demonstrated two unequal 



