TYRINI 305 



Metasternum long, elevated into a flattened surface which is sulcate in 

 apical half. 



Inteimediate coxae widely separated by a space equivalent to trochanter 

 width at apex. Posterior coxae widely separated by a space one half the median 

 metasternal length. 



The intermediate and posterior legs- simple. 



Tarsi three-segmented, relatively short; first segment short and triangular; 

 second twice as long as first; third nearly twice as long as second and obconical, 

 bearing a pair of long, strong, equal claws. 



The anterior legs are profoundly modified: they measure 1.8 mm. in length, 

 well over two-thirds the body length (femur 0.73, tibia 0.8 and tarsus 0.27 mm.) 

 and are in an arc. The femur is greatly inflated dorso-ventrally and flattened 

 laterally, with the narrow inner face densely setose. The tibia is longer than the 

 femur, strongly arcuate and very thin in contrast to the large femur; it is cari- 

 nated along the concave inner face, which also is densely pubescent. The rela- 

 tively short tarsus articulates basal of the tibial apex so that the latter extends 

 nearly to the apex of the second tarsal segment. 



Described upon a single male specimen, collected by Dr. Williams in leaf 

 mold (Sample 1118) of the rain forest of Barro Colorado Island, Gatun Lake, 

 Panama Canal Zone, on July 17, 1938. 



In its essential structural features this genus is tyrine, in the development 

 of the antennal club it is allied to the ctenistine and hybocephaline stems; the 

 maxillary palpi agree with Ephimia with respect to the stiff setae but not the 

 shape of the distal palpomere. This is another instance which suggests that the 

 hybocephaline Ephimia, unknown from the American mainland, belongs in the 

 Tyrini near Juxtahamotopsis. 



LETHENOMUS (Raffray, 1895) 



This is a monotypic Chilean genus equally isolated as Juxtahamotopsis by 

 virtue of its maxillary palpi. These latter organs are four segmented, with an 

 extremely small first segment; second elongate, slender in basal half, gradually 

 broader to apex where the segment is nearly four times as wide as base, with a 

 rounded apex; third similar in form to the second, two-thirds as long, and as 

 wide, with the internal apical face subangulate ; fourth segment unique in the 

 tribe, much longer than second and much wider, with a slender base and a 

 swollen, perfectly rounded apex. This apex lacks a palpal cone and its contour 

 is unbroken ; however, the internal face near apex is produced into an acute tooth 

 which is pubescent. (PI. XX) 



villosus (Schaufuss). 1886. (Aplodea) Chile. Genotype. 



APHARUS (Reitter, 1882) 



This genus holds four species, all of which are South American. The group 

 is closely related to the subgenus Hamotus, differing in having a narrower ab- 

 dominal margin, a very long first visible tergite, and in having the sulcus of the 

 internal face of the distal palpomere limited to the apical half. All three of these 



