NO. 1 BARNARD: AMPHIPODA OF THE FAMILY AMPELISCIDAE 41 



Ampelisca macrocephala (Lilljeborg) 

 Plate 29 



Ampelisca macrocephala Lilljeborg (1842), Ofv. Ak. Forh., vol. 9, 

 p. 7; Sars (1895), Crust. Norway, vol. 1, pp. 172-173, pi. 60, 

 fig. 1; Stebbing (1906), Das Tierreich, pt. 21, p. 101; Holmes 

 (1908), Proc. U.S. Natl. Mus., vol. 35, no. 1654, p. 510. 



Description of female: Head nearly as long as first 3 body segments, 

 anterior margin slightly incised, lower margin oblique, nearly straight. 

 Upper pair of eyes near anterior margin of head, lower pair at infero- 

 anterior angle of head. 



Antenna 1 reaching to the middle of or to the end of article 5 of 

 antenna 2; article 2 of peduncle twice as long as article 1, article 3 

 slightly shorter than 1. 



Antenna 2 more than half the length of the body; article 5 of 

 peduncle three fourths as long as 4. 



Mandible: spine row with 8 spines; article 3 of palp two thirds as 

 long as article 2. 



Maxilla 1: outer plate armed with 10 spines; article 2 of palp 

 nearly as large as outer plate, apex armed with 5 spines, 4 cusp teeth 

 and 7 to 9 setae. 



Maxilliped: inner plate not quite reaching to middle of palp article 

 2, apex with 2 chisel teeth; outer plate reaching to middle of palp ar- 

 ticle 3, inner edge with 8 chisel teeth, rounded apex with 5 spines, the 

 outer 3 plumose. 



Coxae 1 to 3 : lower posterior angle slit. 



Gnathopod 1 : article 6 two thirds as long as 5, article 7 about two 

 thirds as long as 6 ; palm slightly convex. 



Gnathopod 2: article 6 less than half as long as article 5, article 7 

 half as long as 6. 



Peraeopod 1 : anterodistal margin of article 4 very slightly produced ; 

 article 7 half again as long as articles 5 and 6. 



Peraeopod 2 similar to 1 but with generic differences. 



Peraeopod 3 : posterior margin of article 5 with 2 or 3 sets of spines, 

 posterior edge of article 6 with 1 spine. 



Peraeopod 4 : posterior margin of article 5 with 2 or 3 sets of spines, 

 posterior margin of article 6 with 1 spine. 



Peraeopod 5: inferior margin of posterior lobe of article 2 nearly 

 truncate, extending downward almost to end of article 4; article 4 as 

 long as article 3, with a small posterior, setose lobe; articles 5 and 7 

 subequal in length, shorter than article 6. 



