SUBTERRANEAN AMPHIPOD STYGONECTES 25 



with 1 setae each; posterior corners distinct, acute to subacute; 

 ventral margins of plates 2 and 3 with 3 spines each. Pleopod 1, 

 inner ramus a little longer than pedmicle. Uropod 1 with 35 to 40 

 spines; outer ramus about 80 percent as long as inner ramus, about 

 2/3 as long as peduncle. Uropod 2 with 20 to 25 spines; outer ramus 

 about 2/3 the length of inner ramus which is about equal to pedmicle 

 in length. Uropod 3: peduncle armed laterally with 2 or 3 spinules; 

 ramus with 2 or 3 spines apically. Apical lobes of telson armed 

 with 4 to 6 spines each in males and 5 to 7 spines each in females. 



Type locality. — Stream in Organ Cave, Greenbrier Co., W. Va. 

 The type locality, along with a number of other large caves in this 

 area, makes up what is believed to be one of the most extensive cave 

 systems in the world. Up to 30 miles of passages have been explored 

 in recent years (Davies, 1965). In August 1964, I visited the type 

 locality and, although nearly two mUes of stream passages were bio- 

 logically explored, only 13 topotypes were obtained; all except one 

 specimen were taken in a small tributary stream in the northeastern 

 section of Organ Cave proper. The remaining specimen was col- 

 lected from a rimstone pool in the Hedricks Cave part of the system. 

 Gammarus minus (variety "tenuipes" of Shoemaker, 1940) was much 

 more abundant that S. emarginatus, but, although common throughout 

 the Organ Cave streams, it occurred much more sparsely m the 

 Hedricks Cave stream. Both species were generally found under 

 large gravels, although Gammarus appeared much less cryptic in 

 habit. 



Distribution and ecology. — This species is known only from 

 caves developed in Mississippian limestones that crop out along the 

 eastern margin of the Appalachian Plateau in Greenbrier Co., W. Va. 

 (3 caves) and Garrett Co., Md. (1 cave). A range gap of 120 mUes 

 occurs between Fox Cave in northern Greenbrier Co. and John 

 Friends Cave in Garrett Co. Future, intensive biological exploration 

 of caves and possibly seeps along the Allegheny Front in West Vir- 

 ginia will probably reveal more populations of this species. 



To date this species is known only from small cave streams and 

 pools. Two of the three collections of S. emarginatus from John 

 Friends Cave also contained specimens of S. allegheniensis, new species, 

 the latter being much more abundant on both occasions. In Fox 

 Cave, S. emarginatus is known only from a single specimen collected 

 along with one specimen of S. spinatus, new species, in August 1958. 

 On another collecting trip to this cave in April 1965, only a few speci- 

 mens of S. spinatus were obtained. S. emarginatus also occurs syn- 

 topically with S. spinatus in Court Street Cave, which is located 

 about 16 miles south of Fox Cave on the same side of the Greenbrier 



