Tribe 14. Tyrini 



This is an extensive tribe of elegant, large-sized pselaphids distributed 

 over the world, and notable for the generic diversity of the maxillary palpi. 

 The tribe reaches a peak in species and individuals in the tropical forests, 

 and the neotropical forms may be characterized as follows: (1) Pubescence 

 normally long, abundant, and setiform; never in the form of scales, but at 

 times very sparse, short, and thick-shafted (this separates the tyrines from 

 the ctenistines) ; (2) head generally with prominent, multi-faceted eyes placed 

 medianly or postmedianly; the head generally longer than wide, usually nar- 

 rowed anterior to eyes, then more or less widened to form a prominent, median, 

 usually bilobed antennal tubercle. However, in H amotocellus the head is 

 squarely truncate anterior to the eyes, not narrowed, and the widely separated 

 antennae are placed on the angles of the subrectangular front; (3) antennae 

 eleven-segmented, approximate save for H amotocellus, and do not show the 

 startling specific and sexual abnormalities of Batrisini, Brachyglutini, and 

 other assemblages previously covered although some exceptions to this will 

 be encountered in the diagnoses which follow; (4) maxillar\^ palpi four-seg- 

 mented and generically of the utmost value, showing an almost infinite range 

 of variation; (5) the pronotum usually cordiform to ovate, usually with three 

 antebasal foveae which are highly variable in themselves and may or may 

 not be connected by a sulcus ; disc usually simply convex but may be strongly 

 gibbous and medianly spinoid (Neotyrus) ; (6) abdomen with a strong margin 

 each side of the first three visible tergites as a rule ; the tergite length ratio is 

 of importance both generically and specifically; the neotropical genera have 

 six stemites in both sexes, and show little sexual diversity as compared to 

 many other tribes already studied; (7) the trochanters of the intermediate 

 legs are typically macrosceline, elongate and distally enlarged to articulate 

 the femora distally so that femur and coxa are not approximate; (8) tarsi 

 three-segmented, large, the first tarsomere short, the next two relatively much 

 longer of which the third is always the longest and bears two long, equal claws 

 (save for Phalepsus, where the tarsal claws are very unequal). 



Ephimia of the hybocephalines and Ctenistini are the only neotropical 

 pselaphids liable to be confused with this tribe. Ephimia has the two equal 

 tarsal claws very short, and Ctenistini are distinctive as a consequence of 

 their scaly pubescence and the conformation of the epistomal area previously 

 alluded to. 



The general habitat of Tyrini is the leaf and log mold of the forest floor, 

 although many species are exquisitely adjusted synoeketes of the ant society 

 (Park, 1932), or are facultative synoeketes (Park, 1933) and numerous records 

 are extant of their common occurrence with ants (Blatchley, 1910; Dury, 

 1898; Hamilton, 1886; McCook, 1877; Park, 1935; Raffray, 1908; Schwarz, 



(295) 



