MAETNE COPEPODA OF NEW ZEALAND. 33 



The genus Drepanopus which, as proposed by the present writer, included two 

 species, I), furcatus and D. pectinatus, has been divided by Dr. Giesbrecht into 

 two genera — Drepanopus and Clausoc ■alarms, to the latter of which D. furcatus is 

 transferred. The original description dealt with females only, no males having been 

 observed in the ' Challenger' collections. I therefore give here figures of some of the 

 more important diagnostic structures. In some of the New Zealand gatherings both 

 of these species occur together, and when associated with C. arcuicornis and Paracalanus 

 parvus in various stages of growth it becomes by no means an easy matter to 

 separate them. The most conspicuous characters are to be found in the fusions of the 

 antennal joints, the relative lengths of the abdominal segments, and in the structure 

 of the fifth pair of feet in both sexes. 



The anterior antenna? of the female in C. furcatus reach somewhat beyond the 

 extremity of the cephalothorax and are 24-jointed, having all the joints perfectly 

 distinct; in the male (rig. 5) the first and second joints are coalescent, so also are the 

 eighth, ninth, and tenth ; all the rest are distinct. The fifth pair of feet in the female 

 (fig. 4) are very short, two-jointed and alike on both sides ; in the male (tig. 7) the foot 

 of the right side is five-jointed, and about half as long as the abdomen (considerably 

 shorter than in C. arcuicornis), that of the left side is two-jointed and only as long as 

 the first joint of the right foot. The abdomen is four-jointed in both sexes (figs. 3, 7), 

 the first segment being very short, the remaining segments nearly equal in the 

 female, while in the male the third is rather reduced and the fourth rather increased 

 in length. 



Hab. Taken plentifully in the surface-net in Otago Harbour and at Port Chalmers, 

 and in the net at 7 fathoms off Gisborne. 



Genus Acartia Dana. 



1. Acaetia ensifbea, sp. nov. (Plate IX. figs. 8-15.) 



Female. — Seen from above (fig. 8) the cephalothorax is elongated, slightly narrowed 

 towards the front, which is rounded but obscurely angulated in the middle, posterior 

 angles rounded off and entirely without spines ; rostrum obtuse, not furcate ; abdomen 

 about one-third as long as the cephalothorax (fig. 9), composed of three segments, 

 first segment very wide in the adult and equal to the united lengths of the second and 

 third segments ; caudal stylets slender, more than twice as long as broad, longer than 

 either of the two preceding segments. The antennules reach slightly beyond the 

 posterior extremity of the cephalothorax. Fifth pair of feet (fig. 10) two-jointed, 

 basal joint broad, quadrate, its outer margin prominent and mucronate in the middle, 

 whence arises a single very long seta; second joint bulbous at the base and tapering to 

 a long setiform apex. Terminal spines of the swimming-feet (fig. 11) very slender and 

 sword-shaped, with finely pectinate margins. Length T2 millim. 



G 2 



