S6 CLEVE, l^LANKTON FKOM THE INDIAN OCEAN AND THE MALAY ARCHIPELAGO. 



and Re 3 longer then the otlier joints together. Se I, I, 2. Si I, I, 5. St knife-like 

 vvith entire exteriör margin. Re 1 of the 2nd and 3d pair vvith a row of small spines 

 beneath the Se. The surface of Re 2 of the 2nd and 3d p. with a curved row of spines. 

 Re 3 of the 2nd and 3rd p. with some few spines. The proximal part of Re 3 inuch 

 (2, 3, 4 times) longer than the distal and saw-like, but the distal part has entire margin. 

 Ri 3-jointed. Ri 1 shorter than broad. Ri 2 longer than broad and Ri 3 longer than 

 the other joints together. Se O, O, 1 on the 2nd p. O, O, 2 on the other. »Si 1, 2, 5. 

 Ri 2 with several rows of spines. Ri 3 very spinulose. 



Fift/i paii' of legs resembles that of Calocalanus pavo. Left leg 5-jointed; Ri (or 

 the distal 3 joints) lV'2 times longer thaii B (or the 2 proximal joints). B 1 funnel- 

 shaped. Ri 2 somewliat longer than Ri 1 and twice as long as Ri 3. Ri 2 with a small 

 Se. Ri 3 with 2 small S. Right leg not half as long as the left, 3-jointed; joints of 

 almost equal length. The ultimate with a terminal spine longer than the joint. 



Acrocalanus gibber Giesbr. 



(Pl. II, fig. 1 — 16). 



Dlagnosis. The female. Abdomen 4-jointed. Doi-sal margin of Ce very strongly 

 and irregularly convex. Distal exteriör margin of Re 3 of the 4th pair of natatory legs 

 coarsely denticulate. The 5th pa,ir of legs not developed. L. l,i to 1,2 mm. 



The inale. x\bdomen .Vjointed. Dorsal margin of Ce gently and legularly convex. 

 Distal exteriör margin of Re 3 of the 2nd — 4th pairs of natatory legs coarsely denticulate. 

 Of the oth pair of legs the left only developed. L- l,i — 1,2 mm. 



Description of the female. Body (anterior part 0,9, posterior part 0,3) 1,2 mm. 

 Outline of Ce (dorsally) strongly and irregularly convex. Anterior part 4 jointed, Ce ~ Tli 1 

 inore than twice as long as the other joints together. Lateral angies of the last segment 

 rounded. Abdomen 4-jointed; genital segment as long as broad and as long as the two 

 following segments together; anal segment somewhat broader than long. Furca nearly 

 twice as long as broad. St 2 slightly longer than St 3, which is somewhat longer than 

 the nearly equal St 1 and 4. Si faint. St 2 as long as the abdomen. 



■ - . Natatory legs of the 1st pair. B as long as Ri and half as long as Re. B 1 and 

 B 2 of equal length. B 1 without Si but with some stiff' hairs proximally and distally 

 at the exteriör margin. B 2 with a siginoid Si, and distally with some spines and stiff 

 hairs. Re 3-jointed; Re 1 and Re 2 equal, Re 3 shorter than Re 1 and 2 together. Re 1 

 with a row of small spines. Se O, O, 2. St bristle-like and nearly as long as Re. Si 

 1, 1, 4. Ri 2-jointed. Ri i slightly longer than Ri 1. »S«? O, 1; Si 1, 4. 



Natatory legs of the 2nd to 4th pair. B 1 with slightly convex margins, somewhat 

 longer than broad, with 1 short, plumose Si and with several groups of stiff hairs and 

 spines. B 2 broader than long, naked, but on the 2nd and 3rd p. with some spines 

 beneath the insertion of Ri. Re 3-joiiited; longitudinal proportion of the joints as 1:2:3. 

 Se 1, 1, 2. St knife-like, on the 2nd p. as long as Re 3, on the 3d p. ^/i of Re 3, on 

 the 4th p. less than ^/2 as long as Re 3. Si 1, 1,5. Surface of Re 1 of the 2nd and 

 3rd pair with some spines below Se; surface of Re 2 and 3 with numerous spines. Ri 



