6 Mr. G. S. Brady on the Non-parasitic Marine Copeiioda 



thorax, slender and nearly equal in width throughout ; joints 

 about equal in length and breadtli at the base, gradually in- 

 creasing in length towards the apex, the terminal joint being 

 about thrice as long as broad ; each joint bearing a single 

 short delicate hair on the external margin, the twenty-second 

 and twenty-third one on each margin, the last having four 

 or five apical setse. Caudal segments about four times as 

 long as broad ; setai not much longer than the caudal seg- 

 ments. 



llab. One specimen only, taken off Sunderland in the surface- 

 net. 



Genus OiTiroNA, Baird. 



Oithona hehjolandica^ Glaus. 



Oithona helyolandica, Claus (1863), Die frei-lebenden Copepoden, p. 105, 



Taf. 11. ligs. 10-12, 

 O. sjnnifrons ?, Boeck (1864), Oversigt Norges Copep. p. 25. 



Taken occasionally in the surface-net ; plentifully off Sun- 

 derland, August 1871. Frith of Forth, Whitby, and Brid- 

 lington, in gatherings made by Mr. E. C. Davison. 



Boeck's description of 0. spinifrons seems to me not to in- 

 dicate any essential difference between it and 0. helgolandicaj 

 Claus, the chief point being tlie presence of a minute rostrum 

 in the Norwegian specimens, which is not noted in Claus's 

 definition. This, however, might be easily overlooked. I 

 have seen it in some of my examples, but have not succeeded 

 in bringing it into view in others, and should, in fact, have 

 probably missed it altogether, had it not been for M. Boeck's 

 description. 



Genus Boeckia, nov. gen. 



Like Gyclo2nna in general appearance. Superior antennsB 

 very short, six-jointed, much shorter than the ccphalothorax. 

 (Mouth-organs totally different from those of any of tlie allied 

 genera.) Swimming-feet like those of CyclopSy but very short 

 and broad. Fiftli pair of feet one-jointed, laminar, spinous. 

 Abdomen much elongated ; tail-seta3 short ; ovisacs two. 



Doeckia arenicola^ n. sp. 



Second joint of superior antennai the longest, three times as 

 long as broad ; fourth and fifth joints of equal length, two thirds 

 as long as the second ; sixth joint scarcely as long as tlie pre- 

 ceding ; third the shortest of all, about one-fourth as long as 

 the second. Inferior antennae short and thick, three-jointed, 

 without any secondary branch, densely beset with rather short 

 and stout seta?. Swimming-feet having the marginal angles 



