280 NEOTROPICAL PSELAPHIDAE 



may be present, and the elytral flanks lack f oveae, sulci or carinae ; the sutural 

 stria of each elytron, however, is strongly developed; (6) Abdomen with five 

 visible tergites and six sternites in both sexes ; first tergite conspicuously longer 

 than second ; first two sternites long, the second varying from slightly longer to 

 much longer than the first; (7) The posterior coxae are only moderately sepa- 

 rated by a distance which varies from one-third to nearly one-half the median 

 metasternal length; (8) Three-segmented tarsi with the first tarsomere very 

 short; next two relatively elongate, the second longest and elongate-obconical 

 while the third is thinner, cylindrical and bears a large, acute claw and an 

 accessory bristle. 



The size is small and the body typically thick, convex, and more or less 

 ovoidal. They appear to inhabit the forest floor mold by day and the species are 

 probably much more numerous and widely spread than our meagre knowledge 

 indicates. 



The following species are new: 



Batrybraxis panamaensis new species 



Holotype Male. 0.93 mm. long; 0.50 mm. wide; antennae 0.4 mm. long. 



Light brown with legs, maxillary palpi, and swollen seventh antennal seg- 

 ment yellow; integument shining, uniformly but minutely punctulate; pubes- 

 cence flavous, moderately long, abundant, and semierect on body save abdomen 

 where it is subappressed. Temporal beard well-developed. 



Head transverse and structurally very complex; tempora very short and 

 wide, only half as long as eyes; eyes small, far down on sides of head but promi- 

 nent, placed in basal third, and composed of about 32 small facets. Occiput me- 

 dianly, longitudinally sulcate. Vertex high, transversely vaulted from occiput 

 to opposite anterior eye margins, and at this point the vaulted area is abruptly 

 and vertically declivous. This transverse declivity forms a crest which is modi- 

 fied as follows: the median third of the crest is lower than the lateral thirds and 

 holds a pair of erect, oblong, truncate horns while each lateral third of the crest 

 is in the form of a laminoid plate which becomes lower nearer each eye. The head 

 is laterally excavated anterior to the eye as usual by a narrow, pubescent, deep 

 and parallel-sided incisure. The vertexal f oveae are not discernible as such. The 

 vertex just anterior to the transverse crest (in line with the lateral incisures) 

 is ornamented by a median, semi-circular crest whose posterior edge is roundly 

 elevated into a subcornuate pubescent process which nestles against the median 

 horns of the transverse crest. What I take to be the homologues of the vertexal 

 foveae are two roughened depressions, one at each end of the just noted semi- 

 circular crest, these indentures probably mark the anchorage of the supra- 

 tentorium to vertex. The inter-antennal line of the front is marginally tumid 

 and semi-circular in outline, with a small foveoid indenture each side which 

 marks the articulation of the first antennomere. Clypeus simply vertical. Ventral 

 surface of the head perfectly simple. 



Maxillary palpi as described for genus. 



Antennae eleven-segmented, distant, abnormal; segment I elongate-cyl- 



