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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 49. 



R. liostiferus Rehn the anterior tarsi have but three segments. The 

 general structure of the head and body is as in Ceuihoplidus. The 

 subgenital plate of the male is apically deeply divided, the angles 

 elongate, of the female apically entire; cerci of both sexes cylindrical 

 and tapering gradually to a point. 



Besides R. validus Scudder, type of the genus, there is to be referred 

 to this genus the aUied Phrixocnemis hellicosus of Scudder and the 

 somewhat aberrent Phixocnemis liostiferus of Rehn. This last species 

 is distinguished most lemarkably by having the anterior tarsi with 

 but three segments, as mentioned above in the generic diagnosis. 

 The only other members of this subfamily with three segmented 

 anterior tarsi, so far as known to me, are the two species of Daihinia, 



where, however, the hind tarsi are also three- 

 jointed. Another character in which hosii- 

 ferus differs from the more typical members 

 of this genus is the structure of the pos- 

 terior tarsal segments, which are prolonged 

 posteriorly beneath as very long acute an- 

 gles (fig. 24). 



A male specimen in the United States 

 National Museum from Colorado Springs, 

 Colorado, which I have referred to R. lios- 

 tiferus with some doubt, is somewhat larger 

 than the female holotype, and the posterior 

 femora are armed beneath at the apical 

 third on the outer carina with a single very 

 long heavy spine with a few black-tipped 

 serrations following it, the inner carina 

 armed on the apical three-fourths with sev- 

 eral similar serrations. This armature is very 

 different from that of either of the other two 

 Fig. 24.— RHAcnocNEMis hosti- known spccics of the genus. 



The allotype of Scudder' s Phrixocnemis 

 truculentus, a single female from Colorado, 

 is not conspecific nor congeneric with the male holotype from 

 Nebraska, but is a Rhachocnemis and a synonym of R. liostiferus 

 Eehn, with which it agrees, except that one of the spines of the outer 

 ventral carina of the hind femora is decidedly larger than the others, 

 while in the holotype of liostiferus, which is in the United States 

 National Museum, there is no such inequality. The fact that the 

 anterior tarsi of liostiferus are three jointed evidently escaped the 

 notice of both Scudder and Rehn, as neither make mention of this 

 peculiarity. 



Type of the genus. — Rhachocnemis validus Scudder. 



FEEUS. Hind TIBIA AND TAKSU3 

 OF FEMALE TYPE, INNER SIDE. 



