SUBTERRANEAN AlVIPHIPOD STYGONECTES 75 



than antenna 2, with 22 primary flagellar segments; palmar margin 

 of 1st gnathopodal propod more concave than in S. hayi and less 

 concave than in S. t. potomacus; uropod 2 with more spines than 

 in S. t. potomacus and fewer spines than in S. hayi. 



Remarks. — The rapid expansion of metropolitan Washington, 

 D.C., in the past 50 years has undoubtedly resulted in the destruction 

 of a number of former habitats of interstitial amphipods and severely 

 disturbed many others. Both morphologically and ecologically, 

 S. tenuis s. lat. and S. hayi appear to be closely related species, but 

 under natural environmental conditions they are apparently able 

 to maintain the integrity of their respective gene pools. Under new 

 conditions, such as those possibly brought about by extensive urban- 

 ization, ecological isolating mechanisms necessary for mamtaining 

 the separation of these species could have been disrupted. Although 

 future collecting in the Suitland-Forestville area might prove other- 

 wise, I have, tentativeh", interpreted this unique material as represent- 

 ing a possible hybrid form between two otherwise morphologically 

 distinct species. 



Stygonectes alabamensis alabamensis (Stout), new status 



Figure 18 



Crangonyx alabamensis Stout, 1911, pp. 569-571, figs 187, 188 [Type locality: 



well, 1 mile E of post office. Auburn, Lee Co., Alabama]. 

 Eucrangonyx alabamensis (Stout). — Spandl, 1926, p. 77. — Chappius, 1927, p. 78. 

 Synpleonia alabamensis (Stout). — Schellenberg, 1936, pp. 35, 40. — Shoemaker, 



193S, p. 140.— Hubricht, 1943, p. 711.— Barnard, 1958, p. 74.— Hubricht, 



1959, p. 878.— Nicholas, 1960, p. 129.— Bousfield, 1963, p. 1. 

 Boruta americana Mackin, 1935, pp. 46-49, pi. 10 [Type locality: seeps in the 



Sans Bois INIts. near Wilburton, Latimer Co., Okla.]. 

 Synpleonia americana (Mackin). — Schellenberg, 1936, p. 40. — Shoemaker, 1938, 



p. 139.— Hubricht, 1943, p. 711.— Barnard, 1958, p. 74.— Hubricht, 1959, 



p. 878 (in part).— Nicholas, 1960, p. 129. 

 Stygonectes americanus (Mackin). — Holsinger, 1966, pp. 120-122 (in part). 

 Synpleonia clantoni Creaser. — Hubricht and JNIackin, 1940, p. 206 (in part). — 



Mackin, 1941, p. 30 (in part). 



Material examined 



ALABAMA. — Lee Co.: well 1 mile E of Auburn, female lectotype, C. F. Baker, 

 Oct. 18, 1898 (USNM 43463); 20 topotypes, L. Hubricht, Apr. 14, 1941 (USNM 

 and LH). Additional material as follows (collected by L. Hubricht, in LH, 

 unless otherwise indicated): Alabama. — Wilcox Co.; seep, 2.3 miles S of Oak 

 Hill, Apr. 10, 1960. Arkansas. — Benton Co.: seep near Big Spring, Bella 

 Vista, May 7, 1940; Boone Co.: small seeps, Boston Mts., 9 miles SW of Harrison, 

 Apr. 8, 1939; Izard Co.: Bergman Cave, 2 miles NE of Calico Rock, D. Martin, 

 Jan. 22, 1964 (JRH) ; Jackson Co.: small spring, 1.5 mile SW of Olyphant, Apr. 

 11, 1936 (USNM, in part); Logan Co.: seep, 0.6 mile E of The Lodge, Magazine 

 ]\It., May 4, 1940; Newton Co.: small seeps in Boston Mts., 4 miles S of Boxley, 

 Apr. 8, 1939; seeps in Boston Mts., below Lookout Point, 7 miles S of Jasper 

 242-803—67-^6 



