THREE SPECIES OE HARPACTID COPEPODA. lil 



2nd basal joint less produced outwards than in Ancorabolus. 1st pair with both rami 

 2-jointed and subequal in size. Inner ramus of three following pairs well developed, 

 2-jointed, shorter than the outer. Last pair of legs very similar in character to those 

 of Ancorabolus. 2nd pair of legs in male armed at the tip of the inner branch with a 

 curved spine of considerable size. 



Aethropstllus serratus, G. O. Sars, var. spinifera, Norman. (PI. 30. figs. 1-14.) 



1909. Arthropsy Hits serratus, G. O. Sars, Crustacea of Norway, vol. v. Copepoda, Harpacticoida, 

 p. 318, pi. 214. 



Body depressed ; head broadest, thence gradually tapering backwards ; segments well 

 marked. Cephalon broad, about as broad as long ; rostrum widely rounded and slightly 

 prominent ; lateral margins of cephalon slightly notched behind the rostrum, followed 

 by three lateral lobes, of which the middle one is the shortest and the posterior armed 

 with a spine. Segments of the body and first three of the urosome armed with large, 

 falcate, sharply-pointed lateral processes. The body-segments and two earlier segments 

 of the urosome furnished posteriorly with four small spines. The 3rd segment of the 

 urosome bears only two such spines. The last two segments of the urosome subequal, 

 the terminal being rather shorter. Caudal rami subequal in length to three segments 

 of the urosome, bearing two spines on the outer margin, three small terminal, and the 

 long final seta which, together with the rami, equals the length of the entire animal 

 except the head. 



Anterior antennae 3-jointed, moderately stout and long ; joints nearly equal, bearing 

 numerous spines. 



Posterior antenna; consisting of two equal joints and entirely devoid of a secondary 

 branch ; the 1st joint with two setae on the outer margin, the 2nd with two spines on the 

 inner margin, and terminating with five seta?. 



Posterior maxillipeds with the hand elongately ovate, terminal claw unusually long 

 and slender. 



1st feet with two branches subequal in length and 2-jointed; inner ramus terminating 

 in two long seta?, outer with one seta on the 1st joint, two on the 2nd, and three at the 

 extremity. Succeeding feet with the outer ramus 3-jointed, and the inner is much 

 shorter than the outer, 2-jointed, the 1st joint very short. The setose armature is 

 nearly similar to that of the 1st pair, except that the 2nd joint of the exterior branch 

 carries a long seta on its iDner face. 



The 5th feet have the outer branch long and narrow, five or six times as long as 

 broad, with two seta? on the outer margin and three terminal, of which the central is 

 much the longest. The basal joint has the interior produced lobe with four setae, and 

 is about half the length of the terminal joint. 



Length - 7 mm. 



Male with antennules very stout, 6- or 7 -jointed; 3rd joint greatly swollen, terminal 

 strong, nail-like. 



