G. M. Thomson. — On the New Zealand Copepoda. 105 



Hah. Taken abundantly with the dredge in Dunedin Harbour. 



This species was originally described by Dr. Claus from the Mediter- 

 ranean (Messina) ; the specific name refers to the scissor-like appearance of 

 the caudal forks and setas. The European specimens appear to be smaller 

 than ours, being only 0*8 mm. (g 1 ^ of an inch) in length, but in other 

 respects are very similar. 



Genus Harpacticns, Milne-Edwards. 



"Body elongated, or broad and depressed. Head united with the first 

 thoracic segment ; first and second abdominal rings coalescent in the 

 female. Anterior antennae 8- or 9-jointed ; fifth and sixth joints swollen in 

 the male. Mandible-palp 2-branched, large. Posterior foot-jaws strongly 

 developed. First pair of feet with outer branch 3-jointed, first and second 

 joints elongated, third rudimentary ; inner branch 2-jointed, terminal joint 

 very short. Three following pairs of feet with both branches 3-jointed ; 

 in the male, the inner branch of the second pair modified by having the 2nd 

 joint produced into one or more spines, while in the third foot the outer 

 branch is converted into a stout clasping organ, which is bent across the 

 inner branch, and has its last joint armed with several strong spines. 

 Ovisac single. 



1. Harpacticus chelifer, Miiller. PL VI., figs. 12-16. 



(Arpactieus bairdii, mihi, Trans. N.Z. Inst., vol. xi., p. 259.) 



In the description already given of this species I have made one or two 

 errors, which in the absence of a clear description of H. chelifer, led me to 

 consider my specimens to belong to a new species. The anterior antennas 

 are 9- (not 10-jointed), and the relative length of the joints (in the female) 



is as follows : — 



I, 2, 3, 4, 5, 6, 7, 8, 9, 



II. 18. 20. 20. 7. 8. 4. 3. 4. 



In the male, the anterior antennas are hinged between the fourth and 

 fifth joints, the fifth and sixth being swollen and corrugated. The hand of 

 the posterior foot-jaw is subtriangular, and externally very convex, its inner 

 margin being somewhat abruptly angled, strongly excavate and furnished 

 with numerous spines ; its apex bears one (or two) falciform claws. 



The first pair of feet have the inner branch 2- (not 3-) jointed, and ter- 

 minating in two claws. The second foot in the male has the median joint 

 of its inner branch externally produced into a long spine, which greatly 

 exceeds in size the small third joint. The outer branch of the third foot 

 in the male is furnished with three strong spines at its apex, and is bent 

 across the inner branch. In the fifth foot of the male, the basal joint is 

 obsolete. 



This species is common in the European seas, and is by far the most 

 abundant of our littoral Copepods. 



