TYCHINI 279 



Posterior coxae widely separated by a distance equal to three-fourths the 

 median metasternal length as in Dalmodes and Bythinophysis. 



Intermediate trochanters each with a long, oblique, translucent spine on 

 ventral face. Femora not inflated, but tibiae, especially the posterior pair, ar- 

 cuate. Tarsi long (posterior pair nearly two-thirds as long as their tibiae) , three- 

 segmented ; first tarsomere short, obconical-triangular ; last two relatively very 

 long as usual, with the second longest and the third bearing a long, acute tarsal 

 claw. 



Described on a single male specimen, collected April 20, 1924, at Kartabo, 

 British Guiana, in the nest of a new species of Anoplotermes (Anoplotermes) 

 by Alfred Emerson. Professor Emerson's field notes disclose that the beetle was 

 collected unnoticed with tennites of the colony and discovered later in the vial. 

 There are no ecological data to show this species is a definite termitophile but 

 the fact that it was collected with the termites indicates toleration by the host 

 and hence we can suggest that guianensis is a synoekete. On the other hand, the 

 well-formed eyes and wings as well as the normally formed mandibles and max- 

 illae suggest a nonsymphilic role. These latter characteristics are to be treated 

 with reserve since some true symphiles (Fustiger) have both eyes and wings, 

 although the mouth-parts are reduced, while other pselaphids live a nonsym- 

 philic, predaceous life, but are blind and wingless. 



The new genus and species is a welcome addition since it adds a species to 

 the few pselaphids associated with Isoptera, and is one of the very few psel- 

 aphids recorded from British Guiana. In the 1908 Raffrayan arrangement 

 Anoplobraxis becomes associated with Dalmodes and Bythinophysis in the 

 tribal key but is rapidly separated from these two aggregates since they have 

 the elytral flanks longitudinally sulcate. 



BATRYBRAXIS (Reitter, 1882) 



This is an important genus of neotropical Tychini, organized on the follow- 

 ing combination of characters: (1) The head is large, more or less transverse 

 and the vertex, front and ventral surface of the head are often very complex, 

 armed, excavated or fasciculated in the male sex whereas the females are gen- 

 erally conservative and appear very differently from males of the same species; 

 (2) Antennae eleven-segmented, widely separated on the antero-lateral angles 

 of the head, and often highly abnormal in the male sex, this range of abnormal- 

 ity varying greatly among the species; (3) Maxillary palpi four-segmented, 

 moderately elongate and slender; first segment always very small, obconical to 

 subcylindrical; second much longer, elongate, slender and arcuate in basal half 

 and strongly inflated near apex; third obconical, about as wide as second, but 

 from a third to a fourth as long, much longer than wide; fourth widest and 

 longest, varying from cuneiform to securiform, with the apex bearing a palpal 

 cone; (4) Pronotum transverse, with evenly convex, simple disc and transverse 

 antebasal sulcus connecting a lateral fovea each side ; at this level the pronotum 

 is usually suddenly naiTower, or the pronotal outline may be subcordiform; 

 (5) Elytra are simple, they lack basal foveae, although faint dorsal depressions 



