522 Coleopterological Notices, VII. 



EUMICRTNI. 



Within this tribe are included forms which differ profoundly 

 from all other Scydmgenidae in the elongation of the posterior 

 trochanters, in the possession of a large vertical and convex 

 pygidium, and in having the segments and sutures of the abdo- 

 men arcuate. All of these characters are preeminently and essen- 

 tially pselaphidous in nature, and show that the Eumicrini make 

 a closer approach to the Pselaphidse than any other known types 

 of the present family. The Eumicrini include also some of the 

 largest and most specialized forms of the family, having in fact 

 very much the same relationship with the ordinary Scydmaenidas 

 subulipalpi, that the Ctenistini and Tyrini bear to the Bryaxini, 

 for example. 



The genera are moderately numerous, and have been involved 

 in considerable ambiguity hitherto. In the recent European cata- 

 logue of Heyden, Reitter and Weise, there are included under the 

 head of Scydmsenus, the subgenera Microstemma of Motschulsky, 

 having for its type tarsata Miill, Eustemmus of Reitter, having as 

 types antidotus and some other species, none of which are before 

 me now, and Scydmsenus in sp., with rufus Mull, and hellwigi 

 Fab., for its types among others, and having for a synonym Cho- 

 lerus Thoms, Eumicrus is alleged to be a synonym of Scydmas- 

 nus in its comprehensive sense. 



Now the most obvious inconsistency in this arrangement comes 

 from the fact that the subgenus Scydmsenus of Reitter, contains 

 at least two perfectly distinct genera, one having for its type 

 rufus, the type of Cholerus Thoms., with the side-pieces of the 

 metasternum completely covered by the elytra and not approach- 

 ing the hind coxae, and the other represented by hellwigi, which 

 is constituted throughout exactly like our zimmermanni, with 

 distinct met-episterna, which partially enclose the hind coxae. I 

 would propose, therefore, the following scheme for generic types, 

 which would seem to be suflficiently exact and impartial. 

 Eustemmus Reit. — tj^pe antidotus Germ. 



Eumicrus Lap. (syn. Microstemma Mots.) — type tarsatus Miill. 

 Cholerus Thoms. — type rufus Miill. 



For the reasons stated above, hellwigi and zimmermanni, with 

 congeneric species, must receive a new name, and it is probable 

 that the Australian Heterognathus, of King, will prove to be valid 



