SUBTERRANEAN AMPHIPOD STYGONECTES 23 



Stygonectes emarginatus (Hubricht), new combination 



Figure 2 



Synpleonia emarginatus Hubricht, 1943, (in part), pp. 707-708, pi. 9 [Type 

 locality: Organ Cave, Greenbrier Co., W. Va.]. — Barnard, 1958, p. 74. — 

 Hubricht, 1959, p. 878.— Nicholas, 1960, p. 130. 



Material examined 

 WEST VIRGINIA. — Greenbrier Co.: Organ Cave, male and female cotypes 

 (syntypes), L. Hubricht, August 1939 (USNM 79327); Organ Cave, J.R. Hol- 

 singer and C. Maus, Aug. 22, 1964 (JRH) ; Court Street Cave ( = Hayes Cave 

 of Hubricht, 1943), L. Hubricht, Aug. 24, 1939 (LH), and J.R. Holsinger, Aug. 

 21, 1964 (JRH); Fox Cave, T. C. Barr, Jr., Aug. 18, 1958 (LH). Maryland.— 

 Garrett Co.: John Fi-iends Cave, J. Hardy, Aug. 23, 1950 (USNM); J. GiUespie, 

 June 3, 1961 (JRH); J.R. Holsinger, July 18, 1962 (JRH). 



Diagnosis. — Distinguished from other species of the emarginatus 

 subgroup, except S. stellmacki, by larger size, more setose 4th and 

 5th peduncular segments of 2nd antenna, larger number of long 

 setae on mandibular palp segments 2 and 3, and by more distinctive 

 posterior corners of abdominal side plates. Distinguished from S. 

 stellmacki by havmg fewer apical spines on telson and by additional 

 diagnostic characters given for that species. Largest males, 9.75 

 mm; largest females, 13.50 mm. 



Corresponding to the description by Hubricht (1943) with the 

 following additions and modifications: 



Antenna 1 about twice as long as antenna 2, 50 to 60 percent as 

 long as body. Antenna 2: peduncular segments 4 and 5 with 3 or 

 more sets of rather long, stiff setae. Third segment of mandibular 

 palp rather slender, with up to 12 long setae; second segment of palp 

 with up to 14 setae. MaxUla 1, inner plates with 7 or 8 apical, 

 plumose setae. Maxilla 2, inner plate with 7 to 9 long, obliquely 

 placed, plumose setae. Outer plate of maxilliped extending nearly 

 to or as far as apex of 1st palpal segment. Lower lip with small 

 inner lobes. 



Gnathopod 1 : posterior angle of propod with 3 to 5 (usually 4) 

 large, unequal spines on outside, 4 or 5 smaller spines on inside; 

 dactyl claw rather short. Gnathopod 2: posterior angle of propod 

 with 1 large spine on outside, 2 or 3 small spines on inside; posterior 

 margin with 6 to 8 sets of setae; dactyl claw rather short. Coxal 

 plates of pereopods 2 and 3 marginally with 3 spinules and up to 7 

 or 8 setae each; that of pereopod 4 with 9 or 10 marginal setae. Pere- 

 opods 5 and 6, bases broader proximally than distally. Pereopod 7 

 slightly longer than pereopod 6, about 20 percent longer than pere- 

 opod 5; basis about as broad proximally as distally. Dactyls of 

 pereopods 5-7 about 30 percent as long as corresponding propods. 

 Gills absent on 7th pereopods and 1st pleonites; all other gills present. 



Abdominal slide plates with posterior margins convex and armed 



