52 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 109 



mesiad, then laterodorsad; 4 small sharp spines on outer surface of 

 postcingular portion of telopodite; a small knoblilve apical soleno- 

 merite; precingular portion of telopodite much longer than post- 

 cingular portion. Prefemoral spine absent. 



Color faded, but indicates bimaculate pattern. 



Type locality: Trace Creek, Greensbury, Green County, Ky. 

 Known only from the type locality. 



Type specimen : In the U. S. National Museum. 



Discussion : Although this species was first described by Hoffman 

 (1948b) as Tucoria viridicolens, it lacks the complexity of the distal 

 portion of the telopodite of the male gonopods characteristic of the 

 other species wliich have in the past been referred to Tucoria. It is 

 thus another form intermediate between the old Brachoria and Tu- 

 coria and adds another link to the chain of species connecting them. 



Phylogenetic Relationships 



Any attempt to construct an adequate picture of the phj^logeny of 

 a group with no fossil record is obviously exceedingly difficult. De- 

 cisions concerning relative primitiveness of characters are to a large 

 extent necessarily subjective, and it follows that the process of choos- 

 ing a starting point for an evolutionary tree is one fraught with oppor- 

 tunities for error. Even after a beginning point has been chosen, the 

 construction of the tree itself is a matter of choosing between many 

 possibilities, each of which may have many points in its favor. In 

 spite of the acknowledged limitations of such studies, it is often in- 

 structive to indicate as far as possible the more probable relationships 

 existing within any group of animals under consideration. 



The distribution patterns of the species of Brachoria indicate that 

 the most likely center of distribution for the genus is the general area 

 of southwestern Virginia, southeastern Kentucky, and northeastern 

 Tennessee. The majority of the known forms occurs in this region 

 and, as more collecting is done, new records are being established 

 closer and closer to the area for many species formerly known only 

 from more distant localities. 



I consider Brachoria hansonia to be the nearest of the known species 

 to the primitive type of the genus. The form of the male gonopod in 

 this species is very simple in its structure and could easily have given 

 rise to the more complex gonopods of the other species. In addition, 

 it most closely approaches the basic form in related genera such as 

 Apheloria and Sigmoria. Indeed, if the cingulum were not present 

 there could be no hesitation about placing hansonia in Apheloria. 



It seems probable that Brachoria separanda arose from the hansonia 

 stock and developed the swollen portion of the telopodite of the 



