EEPOET ON THE COPEPODA. 99 



Family III. Harpacticid^, Claus. 



Body cylindrical, or occasionally depressed. Abdomen, in most cases, not sharply 

 separated from the cephalothorax. Anterior antennae short, composed of few (4-10) 

 joints, and scarcely ever reaching beyond the posterior margin of the first body-segment ; 

 in the male adapted on both sides for clasping. Posterior antennae two- to four-jointed, 

 and provided with a small one- to four-jointed secondary branch. Mandibles strongly 

 toothed; palp either simple, consisting of one or two joints, or more complex, and 

 composed of a basal portion with two branches. Maxillae usually well developed, 

 consisting of a dentated cutting segment and a more or less complex palp, which is made 

 up of several setiferous digits, arranged in a somewhat radiated manner. Anterior foot- 

 jaws armed at the apex with several strong teeth, and on the inner margin with several 

 (usually three) wart-like, setiferous processes. Posterior foot-jaw sometimes foot-like, 

 but mostly in the form of a prehensile hand. First pair of feet mostly different from the 

 following pairs, and converted into a prehensile apparatus ; second, third, and fourth pairs 

 adapted for swimming ; fifth pair two-jointed, foliaceous, different in the two sexes, the 

 basal joint usually dilated and embracing the smaller apical joint. Eyes as in Cyclops. 

 Heart wanting, copulative organs in the female symmetrical, in the male usually 

 asymmetrical. Ovisac single, or rarely double. 



The number of Harpacticidae taken during the cruise is very inconsiderable, belonging 

 to eight different genera,* and as many species. The genera represented are the following : 

 — Ectinosoma, Pseudothalestris, Zaus, Miracia, Machairopus, Pontostratiotes, Gonio- 

 psyllus, and Setella ; of these all but Ectinosoma, Zaus, Miracia, and Setella are new. 



Ectinosoma, Boeck. 

 Ectinosoma, Boeck, Oversigt ISTorges Copepoder, 1864. 



Body much elongated, slender; abdomen not separated from -the thorax by any 

 distinct constriction, and remaining unflexed on the body after death. Head small, 

 united with the first thoracic segment. Anterior antennas very short, much attenuated 

 towards the apex, five- to seven -jointed, bearing numerous long setae. Posterior antennae 

 much larger and stronger, three-jointed, and bearing on the first joint a long two- or three- 

 jointed secondary branch ; the last joint bears several strong, spine-like plumose hairs. 

 Mandible slender, deeply cleft at the apex ; palp large, two-jointed, bearing several long 

 setae, and a short, simple, secondary branch, which arises from the first joint. Basal joint 

 of the maxilla strongly clawed, palp divided into numerous marginal setiferous lobes. 

 Anterior foot-jaws two-jointed, broad, provided with two strong terminal claws and 

 marginal setae ; posterior three-jointed, long and slender, second joint the longest. Four 

 pairs of swimming feet, all nearly alike, two-branched, each branch composed of three nearly 

 equal joints. Each foot of the fifth pair is composed of two angular setiferous laminae. 



