SUBTERRANEAN AMPHIPOD STYGONECTES 43 



continuous with posterior margin, with several long spines but no 

 setae. Gnathopods without rastellate setae. Lower lip, inner lobes 

 vestigial or absent. Bases of pereopods 5-7 rather broad; posterior 

 margins convex; distoposterior lobes broad and rather well defined. 

 Abdominal side plates: posterior margins broadly convex, armed with 

 7 to 10 comparatively long setae each; posterior corners distinct, 

 bluntly rounded. Telson not much longer than broad, apical margin 

 convex and armed with up to 18 unequal spines. 



Relationship. — Differentiated from the emarginatus group, to 

 which it appears to be most closely allied, by the characters given 

 above and further by having fewer plumose setae on inner plates of 

 maxillae 1 and 2, fewer spine teeth on propod palmar margins of 

 gnathopods, and by comparatively longer and more fragile spines of the 

 uropods, telson, and pereopods. 



Distribution and ecology. — This group is presently known only 

 on the basis of a single, rather unique species which has been collected 

 from only two caves in Greenbrier Co., W. Va, 



Stygonectes spinatus, new species 



Figure 9 



Synpleonia emarginata Hubricht, 1943, pp. 708-709, pi. 9 (in part). 

 Material examined 



West Virginia. — Greenbrier Co.: Court Street Cave, female holotype and 38 

 paratypes, L. Hubricht, Aug. 24, 1939; 1 female paratype, J. R. Holsinger, Aug. 

 21, 1964; additional paratypes from Fox Cave, T. C. Barr, Jr., Aug. 18, 1958, 

 and J. R. Hoslinger and R. Norton, Apr. 18, 1965. (Holotype partially on slide 

 mount, and 11 paratypes in USNM; remaining paratypes in LH and JRH.) 



Diagnosis. — Distinguished by characters given for the spinatus 

 group, above. Largest male, 4.00 mm; largest female, 7.50 mm. 



Antenna 1 about 50 percent as long as body, 50 to 55 percent 

 longer than antenna 2; primary flagellum with up to 18 segments, 

 the distal 7 or 8 segments rather elongate. Antenna 2, flagellum 

 with 6 segments. Mandibular palpal segment 3 moderately slender, 

 with up to 7 long setae; palpal segment 2 with up to 6 setae. Maxilla 

 1, inner plate with up to 5 apical, plumose setae. Maxilla 2, inner 

 plate with up to 6 long, obliquely placed, plumose setae. Maxilliped: 

 inner plate with 4 thick spines apically; outer plate reaching well 

 beyond apex of 1st palpal segment. Lower lip, inner lobes vestigal 

 or absent. 



Gnathopod 1: propod palmar margin oblique, slightly convex, 

 armed with a double row of about 6 small spine teeth; posterior 

 angle and posterior margin continuous, with 4 large spines on outside 

 and no spines on inside; lateral setae few in number, singly inserted. 



242-803—67 A 



