PSEUDOCALANUS. 45 



1. PSEUDOCALANUS ELONGATUS, Boech, PL III, figS 1—9. 



Clausia elongata, Boeck. Oversigt Norges Copep. p. 10 (1864). 

 Calanus Clausii, Brady. Nat. Hist. Trans. Northumberland and 



Durham, vol. i, p. 33, pi. i, figs. 1 — 



11, 13 (1865). 



Body elongated, ovate, anterior antennas in the 

 female (fig. 2) 25-jointed, the seventh and eighth (or 

 eighth and ninth ?) joints being coalescent, the rest 

 gradually increasing in length and tenuity as they 

 approach the distal extremity : in the male the number 

 of joints is reduced to twenty by the coalescence of 

 several, the seventh, eighth, and sixteenth joints 

 (fig. 3) thus becoming much elongated ; the two or 

 three terminal joints are swollen at the distal extremity 

 and contracted at the base, and in the male some of 

 the other joints are also similarly enlarged ; the outer 

 margin of the antennae is sparingly provided with 

 short hairs. Fifth pair of feet wanting in the female ; 

 in the male (fig. 8) they are long and slender, the left 

 consisting of three cylindrical tapering joints, of which 

 the middle is the longest ; the right of five joints, of 

 which the first three are nearly equal in length, the 

 fourth shorter and the fifth quite minute and claw-like. 

 The first abdominal segment in the female is much the 

 longest and is tumid in front ; in the male it is very 

 short : abdomen 4-jointed in the female, 5- jointed in 

 the male; the caudal segments very short; tail setae 

 also short, scarcely equal to half the length of the 



