16 EEV. T. E. E. STEBBING— BISCAYAN PLANKTON : 



second joint a little shorter, third short ; flagellum of 31-34 joints, ahout thrice as long 

 as peduncle, with suhapical setules, which on the joints of the proximal half form short 

 fringes. Accessory flagellum consisting of a single spine-like joint, about three-fourths 

 as long as the second of the peduncle. 



Second aiitennie. — The gland-cone is veiy prominent on a very short joint. The two 

 following joints are slender, the first half as long as the second, the latter nearly as long 

 as the first of the first antennae. 



Upper lip. — Distal margin straight and smooth in centre, at each end slightly rounded 

 and hirsute. 



JIuudibles. — Cutting-edge and secondary plate not very broad, the teeth small ; spine- 

 row of four spines ; molar moderately powerful, a denticulate oval not occu.pying the 

 Avhole of the crown ; palp elongate, set well forward ; first joint short, second consider- 

 ably longer than the third. 



Ph'sl maxillcB. — Inner plate seemingly very slight ; outer plate with ten spines, some 

 of which have a lateral denticle ; first joint of palp scarcely half as long as second, the 

 latter apically fringed with setse. 



Second maxillce. — Inner plate short, the rounded apex fringed with a few short 

 spinules ; the outer plate little more than half as broad, with several long apical spines. 



Ilaxillipeds. — Inner plates not partially coalesced as in Eusirus, their apical spines 

 slender; outer plates little broader, their spines slender ; second, third, and fourth joints 

 of palp elongate, subequal in length. 



First gnathopods. — Second joint long, distally narrowed, channelled in front, third and 

 fourth joints short, fifth nearly as long as second, its long narrow stem widening to the 

 commencement of the shallow cup in which the trapezoidal hand reposes. The powerful 

 hand, or sixth joint, has four unequal margins, the front one, to the base of which the 

 fifth joint is attached, being the shortest. The longest is the palmar margin, a horny- 

 looking strip fringed with little spinules ; the finger is attached at its base and with 

 curved apex overlaps its distal end, on which are planted two spines, one long, the 

 other short. The other two margins, which meet in a rounded obtuse angle, perhaps 

 together represent the hind margin of this muscular joint. 



Second gnathopods. — These are distinguished from the first by having several long 

 setae on the hind mtirgin of the second and fifth joints, by having the stem of the latter 

 considerably wider, the hand and finger very much smaller, the palm more convex and 

 not overlapped by the finger. Also, the stem of the fifth joint, instead of being not much 

 longer than the part which forms the cup, is here nearly two and a half times as long. 

 In both pairs the finger is shaped to correspond with the palmar margin. 



First and second perceopods. — Extremely slender ; second joint elongate, third short, 

 fourth (in second pair) long, but much shorter than the second. 



Third per(eop)ods. — The side-plates of this pair are very unequally bilobed. 



Fifth perccopods. — The second joint is little longer than broad, with a slight narrowing 

 distally : the fourth joint is a little longer, slender, slightly curved. 



Fleopods. — Peduncle carrying two small coupling-hooks ; the first joint of inner ramus 

 armed with five cleft spines, this ramus (in one pair) having fourteen joints, and the 

 outer fifteen. 



