52 U.S. NATIONAL MUSEUM BULLETIN 259 



D.C., S. pizzinii appears to be comparatively rare. While the 

 extensive collecting operations carried out by Mr. Andrew Pizzini 

 in this area during the 1930s resulted in the location of numerous 

 sites for S. t. potomacus, only a few in comparison were found for 

 S. pizzinii; the most profitable of these (in numbers of collected 

 specimens) being Wetzels Spring. The largest collections of S. 

 pizzinii made to date, however, have been from Refton Cave, where 

 258 specimens were obtained from 8 collections m.ade over a 6-year 

 period extending from 1935 to 1941. Refton Cave is composed 

 essentially of one room (approximately 125X60 ft) which contains 

 a large lake with an abundance of decaying organic material (e.g., 

 leaves and wood). In May 1965, I visited this cave but was unable 

 to find any amphipods after a thorough two-hour search, although 

 a fantastically large isopod fauna (Asellus pricei) and a moderately 

 large planarian population (Speophila pricei) were present. 



Collections have been made from 12 or 13 sites covering every 

 month of the year, but ovigerous females have been obtained from 

 only three localities: artesian well, Frederick Co., Md. (7.50 mm 

 female, April coll.) ; Pequea Silver Mine, Pa. (8.50 mm female, May 

 coll.); and Refton Cave, Pa. (40 females during the months of Jan- 

 uary, March, April, May, and August). In the last, ovigerous 

 females ranged in size from 9.45 mm to 15.75 mm (Mean = 12.45, 

 S.D. = 1.51). A statistical summary of the egg production in Refton 

 Cave females follows (females carrying young not included): N=35, 

 Range=6 to 28 eggs, Mean=-12.31, S.D.=4.9, C.V.=39.80%. 



Remarks. — Hubricht's records for Synpleonia pizzinii (Hubricht, 

 1943) from Skyline Caverns, Warren Co., and Massanutten Caverns, 

 Rockingham Co., Va., are in error. I have assigned material ex- 

 amined by Hubricht from Skyline Caverns to S. gracilipes (cf., 

 description herein). The collection from Massanutten Caverns was 

 determined by Hubricht as Stygobromus spinosus (Hubricht and 

 Mackin, 1940) but mistakenly reported as a record for S. pizzinii 

 (Hubricht, in litt.). The range for S. pizzinii given by Shoemaker 

 (1938, 1942a), Dearolf (1941), and Holsmger (1963, 1964) has been 

 more closely circumscribed as a result of the present study. 



Stygonectes indentatus, new species 



FiGUKE 11 



Material examined 



VIRGINIA. — Nansemond Co.: outlet of drain, 3 miles NW of Suflfolk, holotype 

 male, allotype female, and 80 paratypes, L. Hubricht, Feb. 25, 1945; outlet of 

 drain, 2 miles ESE of Chuckatuck, 200 paratypes, L. Hubricht, Jan. 30, 1944 

 (USNM and slide mounts of a male and female paratype in JRH.) 



