Tribe 9. Goniacerini 



The Goniacerini are highly evolved brachysceline pselaphids, representing 

 one of the apices of specialization in the family. The tribe has few genera and 

 few species. Its zoogeographic penetration is limited to tropical Africa and tropi- 

 cal America, with the latter region being more abundantly represented in both 

 genera and species. 



Taxonomically, Goniacerini are differentiated from other pselaphids by the 

 following combination of characters: (1) head narrowed anterior to the eyes 

 to form a prominent, median frontal antennal tubercle; (2) antennae subcon- 

 tiguously articulated on this tubercle, with a long first segment and strongly 

 geniculate (as in the Metopiini), and with the genera varying in number of an- 

 tennal segments from five to eleven; (3) abdomen with five visible tergites, 

 and six sternites in both sexes ; first stemite longer than posterior coxae, clearly 

 visible from side to side (as in the Tychini) ; abdomen with strongly formed, 

 flattened abdominal margins; (4) trochanters short, with the femora obliquely 

 articulated on them so that the corresponding coxa and femur are subcontig- 

 uous; (5) posterior coxae with their mesial articulating faces subtriangular, not 

 conically produced; (6) tarsus three-segmented, strong, first segment small and 

 triangular, second and third segments relatively much longer than first ; third 

 segment bearing a large tarsal claw and in some groups an accessory bristle-like 

 claw; (7) maxillary palpi short, small, and always appear three-segmented. 

 However, this will probably prove erroneous when all of the genera have been 

 fully investigated. Fletcher (1927) found that the maxillary palpi of Bibrax 

 bradleyi have four segments, but that the first was very minute and visible only 

 after dissection; second strongly arcuate, apically inflated; third ovate-elon- 

 gate; fourth ovate-elongate with an obtusely pointed apex, obliquely truncate 

 at base, with a short thick palpal cone. Raffray (1890) found that the appar- 

 ently three-segmented maxillary palpi of Goniacerus perforatus were in reality 

 four-segmented on dissection, the first relatively large and sharply arcuate. 

 Raffray (1908, p. 295) states that the maxillary palpi are three-segmented for 

 the tribe, (p. 297) demonstrates only three segments for Ogmocerus giganteus 

 of Abyssinia, and later (1908, pi. 8, fig. 55) figures only three segments for this 

 species, although Fletcher (1927) thought that this Raffrayan figure showed 

 four segments. From such data it appears that a great deal of morphological 

 work, especially with prepared microscope slides, needs to be done on the gon- 

 iacerine mouth-parts. 



The individuals of this tribe seem to be very uncommon, and nothing is 

 known of their ecology. The neotropical genera may be separated by the follow- 

 ing key: 



(283) 



