NO. 5 BARNARD : AMPHIPODA 55 



Juvenile animals lack the notch on the anterior edge of article 5 of 

 pereopod 5. 



Holotype: AHF No. 607, ?female, 9.5 mm. 



Type locality: Station 6833, Tanner Canyon, 32°-37'54"N, 118°-5'- 

 40" W, 813 m, January 29, 1960, bottom of green muddy sand. 



Canyon material: 6834(2), 6833(2). 



Ampelisca spp. 



A/fl/ma/; 5925(3), 5940(1), 5942(1), 5943(1), 6834(1). 



Genus Byblis Boeck 



5^/,/f^._Stebbing 1906: 111-112. 



Remarks: Although Schellenberg (1931) had precedent in assign- 

 ing B. subantarctica to Byblis because of the condition of B. anisuropa 

 Stebbing (1908), I am transferring it to the genus Ampelisca and I 

 believe that B. anisuropa also should be removed to Ampelisca. 



Since the early concepts of Ampelisca and Byblis based on Euro- 

 pean faunas were formulated, several intergrading species have been 

 discovered. Byblis differed from Ampelisca in the dense setation on 

 the anteroventral edge of the lobe on article 2 of pereopod 5, between 

 the ventral border and its juncture with the stem of the article. In addi- 

 tion, article 6 of pereopod 5 was narrow and article 7 spiniform. An- 

 other character of Byblis was the short, broad telson, never cleft more 

 than halfway, whereas in Ampelisca the telson was elongated, deeply 

 cleft and had tapering apices. Species such as those named above have 

 been described and assigned to Byblis. They lack the full setation of 

 pereopod 5 but bear the narrow sixth and seventh articles. Those spe- 

 cies also have deeply cleft telsons of medium elongation and they should 

 be transferred to A?npelisca, even though the sixth and seventh ar- 

 ticles of pereopod 5 are typical of Byblis. They join a similar species, 

 Ampelisca byblisoides K. H. Barnard ( 1925). 



This arrangement leaves Byblis with typical setation of pereopod 5 

 and a short telson cleft halfway or less. Byblis subantarctica is very 

 closely related to and possibly synonymous with Ampelisca hemicryp- 

 /o^^ K. H. Barnard (1930). 



Key to Species of Byblis 



1. Corneal lenses absent 2 



1. Corneal lenses present _ 10 



2. Cleft of telson one fourth or less 3 



2. Cleft of telson halfway or more 5 



3. Lateral cephalic lobe with ventral margin parallel to 



dorsal margin of head ceylonica 



