424 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



DiAGXosis: Sides of head straight bc^tween ooni and anterior plate, 

 which is circular in shape, with deeph' incised frons, wide supporting 

 carinae, and large incrassations ; premarginal carinae with marginal 

 half faintly pigmented, also outer portion of nodi, which are semi- 

 circular in shape, the tips curving inward; postmarginal carinae 

 present but pale. 



Prothorax nan-ower in anterior portion, with convex, divergent sides 

 (an unusual shape) ; pterotiiorax large (0.21 X0.36), with rounded sides 

 and short posterior portion. 



The abdomen is large (1.21X0.61), with narrow pleurites, blackish 

 dorsalh" and wider ventrally in anterior and posterior portions. 



The type, and only specimen, is in rather poor condition, having 

 been demounted for clearing, and with much of the chaetotaxy missing, 

 so that the number of setae in ventral patches of sternite VIII cannot 

 be determined. 



The species may be distinguished by the unusual shape of the an- 

 terior plate, the carinae of the head, and the shape of the thoracic 

 segments. 



Formicaphagus brevifrons, new species 



Figure 5,a; 6,e 



Types: Male and female adults from Pyriglena leucoptera (Vieillot), 

 collected by Dr. Werneck at Serra de Angra, State of Rio de Janeiro, 

 Brazil (Hopkins collection). 



Diagnosis: The largest of the known species of the genus (female, 

 2.12 X 0.G7, with abdomen 1.34; male, 1.54 X 0.49). Head wider 

 than long in both sexes, with swollen temples, and in female much 

 wider at base of coni. 



Anterior plate wider than long, wider at tips of premarginal carinae; 

 frons narrow and median incision shallow; the premarginal carinae 

 are of unusual shape and rather complicated for descrii)tion (see 

 fig. 5,a) ; carinae connecting premarginal nodi with posterior mandib- 

 ular condyles narrow. 



Prothorax with sides and posterior margin convex; pterothorax 

 with sides convex and strongly divergent; each side of posterior 

 margin concave and with median point rounded, this character more 

 j)ronounced in the male. 



Abdomen strongly oval in both sexes, with wide pleurites, the 

 light brown ventral portion being more than twice the width of the 

 pitchy black dorsal portion. 



The tergites are but slightly chitinized, but sternites IV and V are 

 nmch more deeply colored than usual. 



The chaetotaxy of the cntu*e body is unusually shoit and coarse, 

 and blackish in color; the patches on each side of segment VIII are 



