170 



Part III. — Thirteenth Annual Report 



outer and inner branches of the first pair of swimming feet. The differ- 

 ence in the form of the fifth pair is also very marked. 



Genus Thalestris, Claus (1863). 



Thalestris mysis, Claus. 



1863. Thalestris mysis, Claus. Die frei lebenden Copepoden, 

 p. 130, PI. XVII. figs. 12-16. 

 Remarks. — This very distinct species was observed for the first time 

 in the Firth of Forth during the last summer. 



Pseudothalestris, Brady (1883). 

 Pseudothalestris pygmsea (T. and A. Scott). 



1895. Pseudowestwoodia pygmiea, T. and A. Scott, Ann. and Mag. 

 Nat. Hist., ser. 6, vol! xv. p. 55, PI. VI. figs. 8-16 (Jan. 

 1895). 



Habitat. — Near Dunbar, at the mouth of the Firth of Forth. In the 

 Annals and Magazine of Natural History for May 1895 we have shown 

 that the genus Pseudothalestris, Brady, which was described in the Report 

 on the 'Challenger' Copepoda (p. 100), from a single specimen — a male 

 — obtained in a gathering collected at Betsy Cove, Kerguelen Island, in 

 lat. 49° 16' S., long. 70° 12' E., is apparently identical with Pseudoicest- 

 woodia, T. Scott, described in the Twelfth Annual Report of the Fishery 

 Board for Scotland. This is another instance of the remarkable similarity 

 that exists among some of the lowly organisms that inhabit opposite sides 

 of the globe. 



Pseudothalestris major (T. and A. Scott). 



1895. Pseudowestwoodia major \ T. and A. Scott, op. cit. p. 56, 

 PI. VI. figs. 17-20. 

 Habitat.- — Vicinity of Granton, and of Dunbar, Firth of Forth. Rare. 



Genus Harpacticus, Milne-Edwards (1838). 



Harpacticus obscurus, n. sp. (PI. IV. figs. 4-12). 



Description of the species. — Female, length '8 mm. (-^ T of an inch). 

 Antenrmles somewhat slender, nine-jointed ; the first four joints are of 

 nearly equal length, the sixth, which is about half the length of the third, 

 is nearly twice as long as the last joint. The proportional lengths of the 

 joints are as shown by the formula — 



Proportional lengths of the joints, 13 • 13 • 1 4 • 13 • 5 • 7 • 3 • 2 • 4 

 Number of the joints, 1* 2 ' 3 ' 4 • 5 ■ 6 • 7 ' 8 * 9 



Antenna? very robust ; secondary branch equal to about three-fourths 

 the length of the end joint of the primary branch, very slender and com- 

 posed of two nearly equal joints (fig. 6). Mandible stout, basal joint of 

 mandible-palp dilated at the end (fig. 7). End joint of the posterior 

 foot-jaw broadly ovate ; a row of small setae extends obliquely across part 

 of the inner aspect of the joint, while a few small setae arranged in a 

 transverse row spring from the vicinity of the outer margin, as shown by 

 the drawing (fig. 8). Terminal claw stout and strongly curved, a slender 

 supplementary seta springs from the inner aspect of the claw near the 

 base; a small seta also springs from the inner distal angle of the first 

 joint. Outer branches of the first pair of swimming feet elongate, moder- 

 ately stout ; first and second joints of nearly equal length, and fringed 

 with minute hairs on the outer edge ; third joint almost obsolete ; the first 

 joint bears two small setae on the outer distal angle, and one small seta 



