NO. 1 BARNARD: AMPHIPODA OF THE FAMILY AMPELISCIDAE 13 



Uropod 3 : rami subequal in length, lanceolate, outer ramus more 

 slender than inner; both rami setose on both margins, inner margin 

 of inner ramus with 6 short spines. 



Telson : lobes broad ; apices notched, each with a single spine ; 

 dorsal surface of each lobe with 3 spines and a seta. 



Pleon segment 3 : posterior margin slightly convex, lower posterior 

 angle nearly quadrate. Dorsal surface of segment with a very low, 

 medial ridge. 



Pleon segment 4: posterior dorsal surface slightly convex, posterior 

 end not raised above pleon segment 5. 



Pleon segment 6: lateral ridges rather well developed. 



Length of male 9 mm. 



Description of female: Antennal peduncles rather slender, antenna 

 1 reaching only slightly beyond end of peduncle of antenna 2, article 2 

 of peduncle of antenna 1 longer than article 1 ; article 6 of gnathopods 

 1 and 2, setal spines not strongly developed, palm not concave; inner 

 ramus of uropod 3 strikingly smaller than outer, with only a few termi- 

 nal setae, inner edge of inner ramus strongly serrate, each serration 

 enclosing a short spine, setae absent ; peraeopods 1 and 2, not as strongly 

 setose as in male; posterior margin of pleon segment 3 not quite as 

 convex as in male; pleon segment 4 not as strongly convex as in male. 



Material examined: Stations 16-33 (1), 82-33 (2), 111-33 (2), 

 114-33 (9), 157-34 (1), 170-34 (1), 171-34 (1), 173-34 (1), 183-34 

 (51), 185-34 (1), 190-34 (16), 201-34 (3), 264-34 (2), 279-34 (2), 

 283-34 (81), 287-34 (2), 306-34 (74), 317-34 (1), 392-35 (2), 

 394-35 (1), 423-35 (2), 433-35 (1), 448-35 (1), 450-35 (1), 466-35 

 (8), 562-36 (1), 696-37 (2), 734-37 (1), 874-38 (1), 1123-40 (1), 

 1155-40 (2), 1170-40 (2), 1232-41 (1), 1269-41 (2), 1280-41 (1), 

 1369-41 (3), 1405-41 (1), 1407-41 (31), 1418-41 (2), 1421-41 (4), 

 1426-41 (3), 1431-41 (5), 1619-48 (1), 1621-48 (2), 1790-49 (2), 

 1905-49 (6), 1944-50 (1), 2014-51 (19). 



Remarks: Holmes' figures indicate that he described a young male, 

 as the third uropods are subequal in length and not strongly setose. 

 There is a considerable difference between the third uropods of the 

 male and female. 



This species closely resembles Ampelisca schellenbergi Shoemaker 

 (1933) in the form of the peduncle of antenna 1, pleon segments 3 and 

 4, shape of head, and uropod 3. It differs from Ampelisca lobata in the 

 anterodistal notch of article 5 of peraeopod 5, the more slender telson, 

 the peculiar attachment of article 6 to article 5 on peraeopod 5, and 

 the lack of spines on the third uropod inner ramus of the female. 



