42 U.S. NATIONAL MUSEUM BULLETIN 259 



slightly concave, armed with a double row of 10 spine teeth; posterior 

 angle with 1 large spine on outside, 4 smaller spines on inside; posterior 

 margin with 4 sets of setae; lateral setae in transverse rows, mostly 

 singly inserted; claw of dactyl long. Coxal plate of pereopods 2 and 



3 with about 8 marginal setae each; that of pereopod 4 with 12 mar- 

 ginal setae. Pereopod 7 about equal in length to pereopod 6, about 

 30 percent longer than pereopod 5. Bases of pereopods 5-7 similar 

 to those of S. gracilipes. Dactyls of pereopods 5-7 about 35 percent 

 as long as corresponding propods. Coxal gills absent on 7th pereo- 

 pods; all other gills present. 



Abdominal side plates: posterior margins convex, with 1 setae each; 

 posterior corners distinct, subacute; ventral margin of plate 2 with 



4 spines, that of plate 3 with 3 spines. Pleopod 1, inner ramus a 

 little longer than peduncle. Uropod 1 with 46 spines; outer ramus 

 about equal in length to inner ramus, 60 to 66 percent as long as 

 peduncle. Uropod 2 with 29 spines; outer ramus a little shorter 

 than inner ramus, which is about equal to peduncle. Uropod 3: 

 ramus about 1/4 as long as peduncle, armed with 3 or 4 apical spines; 

 peduncle with 1 distolateral spine. Telson about 1/3 longer than 

 broad, a little broader proximally than distally, armed laterally with 

 8 spines and apically with 9 spines. 



Type locality. — Breathing Cave, Bath Co., Va. The type series 

 was collected from a small stream in the lower level of the cave 

 (L. G. Conrad, pers. comm.). Breathing Cave is the third largest 

 cave in Virginia with approximately foiu* miles of surveyed passages. 

 It is geologically situated so as to form an integral part of the huge 

 Butler-Sinking Creek — Aqua Cave System located just to the east un- 

 der Sinking Creek Valley and Chestnut Ridge. 



Distribution and ecology. — This species is known only from its 

 type locality where previous biological exploration indicates it to be 

 extremely rare. A number of attempts have been made to find 

 amphipods in other parts of the Butler-Sinking Creek — Aqua Cave 

 System, but to date none of these attempts have met with success. 

 Nothing is known about the life history or reproductive capacity of 

 this species. The holotype female possessed only small, partially 

 developed brood plates. 



Remarks. — It is a pleasure to name this species after its collector, 

 Mr. Lyle G. Conrad, who has to date collected the only known 

 specimens of this rare form. 



SPINATUS Group 



Diagnosis. — Propod of gnathopod 1 about equal in size to that of 

 gnathopod 2 but broader proximally; posterior angle poorly defined, 



