GAMMARIDEAN AMPHIPODA 



73 



sory tooth and 2 accessory setiiles, article 5 poorly lobate posteriorly 

 but with small posterodistal, acute process; gnathopod 2 slender, un- 

 usually short, hand of medium breadth, rectangular, palm transverse 

 or forming slight blunt chela, dactyl large, fitting palm, inserted 

 mediodistally on article 6; pereopods 1-5 generally without specific 

 diagnostic features, pereopods 1 and 2 lacking distinctive posterodistal 

 spines on sixth articles, pereopods 3-5 broken at fifth articles; pleonal 

 epimeron 1 with quadrate anteroventral corner, posterior corner 

 rounded, epimera 2 and 3 with quadrate posteroventral corners; dorsal 

 process of pleonite 4 low, humped ; inner ramus of uropod 2 with deep 

 incision; telson cleft slightly less than halfway, lateral margins bear- 

 ing spines. 



Figure 31. — Schisturella abyssi (Chevreux), female, 5.9 mm, 7230: a, uropod 3; b, maxilli- 

 ped, ventral surface, inner plate hidden and not outlined; c, pleonal epimeron 1, left 

 lateral; d, mandible; e,f, maxillae 1,2; g, inner plate of maxilliped; h,i, distal ends of 

 gnathopods 1,2, minus setae. 



Material. — Station 7230, female, 5.9 mm. 



Kemarks. — The characters of this specimen resemble those of 

 Schisturella a. abyssi much more closely than do those of S. ahyssi 

 tasmanensls (J. L. Barnard, 1961). The small differences of this 

 specimen from that described by Chevreux are: the blunter, more 

 truncated posteroventral corner of the third pleonal epimeron, the 

 shorter posteroventral lobe of article 2 on pereopod 3, the very slightly 

 deeper telsonic cleft, and the slightly broader lateral cephalic lobe. 

 Schisturella a. ahyssi differs from its congeners by the poor develop- 

 ment of the labral lobe. 



