Brazilian Barin^e 269 



hardly be said of Nedestes, and finally that the strial intervals are 

 very convex and that the metasternum at the sides is covered with 

 golden-yellow scales, neither of which characters is suggested here, 

 the intervals being flat and the entire surface glabrous. The color- 

 ation of the body in the type of Xenisus is also quite different, which 

 is a suggestive consideration. It is probable that the habits of both 

 these genera are very similar to those of Balaninus. 



It will be noted that in the preceding enumeration of the genera 

 and species of the Centrinini, I have not been able to even define 

 the genus Centrinus itself. This was founded upon the Baris bicus- 

 pis, of Germar, which, according to the descriptions, differs very 

 much from anything at present known to me. Possibly the genus 

 called Calorida above, may approach it closely; this is known to 

 me only by the female, and is founded upon a comparatively small 

 species. 



Tribe Limnobarini 



As in the case of the Centrinini, it should be stated that the limits 

 of this tribe are not well defined, and there is no very clearly marked 

 boundary separating the two. In fact some genera, such as the 

 Nicentrids, having prominent and non-decussate mandibles, might 

 almost as well be considered a part of the preceding, as of the present 

 tribe. It should be understood, in this connection, that the Limno- 

 barini are merely an association of those Centrinids which have the 

 body parallel in form, or notably narrow, elongate and devoid of an 

 evidently rhombic outline. They include all sorts of structural 

 peculiarities, excepting the essential features characterizing the 

 tribes coming before the Centrinini and those which follow, such 

 as the Madarini and Barini, and, on the whole, it is as sharply 

 isolated as almost any other of the Barid tribal groups that can be 

 at all well differentiated, all of them being inconstant in at least one 

 or two structural characters used to define them. In the nearctic 

 fauna, such diverse genera as Calandrinus, Anacentrus, Haplostethus 

 and Barilepton belong here, and, in the European fauna, several 

 genera having a parallel form of body, besides Limnobaris itself, 

 should also be included. 



One peculiarity of the Limnobarini, as here organized, is the 

 comparatively large number of genera necessary for the known 

 species, there being, as proposed, only about 2.8 species to the genus 

 as a ratio, seeming to indicate that the tribe includes a number of 

 groups which are of very ancient origin, like the nearctic Eisonyx 

 and related monotypic genera, and also in all probability the 

 tropical Madopterini. 



The Brazilian genera of Limnobarini, so far as recognized, are 

 as follows: 



