of the Fishery Board for Scotland. 



167 



more elongate. Antennules short, eight-jointed, the first two joints 

 dilated, second joint longer than any of the others, the fifth, sixth and 

 seventh short, terminal joint about half the length of the second. The 

 proportional lengths of all the joints are shown in the formula — 



Proportional lengths of the joints, 2 1 • 26 • 16 ' 21 • 8 • 9 ' 6 * 13 

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



Antennae stout, secondary branch of moderate length, three-jointed 

 (fig. 3). Basal joints of the mandible-palp dilated, both branches two- 

 jointed, but the end joints are small (fig. 4). Posterior foot-jaws some- 

 what like those of Stenhelia ima, — a plumose seta springs from the 

 inner distal angle of the first joint, a longitudinal and slightly curved 

 row of small hairs extends along the side — interiorly — of the second 

 joint, while the inner margin of the same joint bears two slender setae 

 on the distal half ; two small supplementary setae also spring from the 

 base of the terminal claw (fig. 5). First pair of swimming feet 

 elongate, the last joint of the inner branches is about twice the length 

 of the second, while the entire length of the second and third joints is 

 only about two-thirds the length of the first joint. The outer branches 

 are rather more elongate than the first joint of the inner branches (fig. 

 6). The other four pairs somewhat similar to those of Stenhelia ima, 

 but the secondary joint of the fifth pair is proportionately less elongate, 

 so that the inner portion of the basal joint extends to about two-thirds 

 the length of the secondary joint (fig. 8). Caudal stylets very short, the 

 principal seta of each is interiorly gibbous at the articulation near tiie 

 base (fig. 9). 



Habitat. — Shore near Dunkar, Firth of Forth. Rather rare. 



Remarks. — This species may be distinguished from Stenhelia ima, 

 Brady, which appears to be its nearest ally, not only by its greater length, 

 but also by the length and structure of the antennules, and by the pro- 

 portionally longer inner branches of the first pair of swimming feet. 



Genus Mesochra, Boeck (1864). 



Mesochra spinicaudata, T. and A. Scott. 



1895. Mesochra spinicaudata, T. and A. Scott, Ann. and Mag. 

 Nat. Hist., ser. 6, vol. xv. p. 52, PI. V. figs. 12-25. 

 Habitat. — In pools near low-water on the shore at Musselburgh, Firth 

 of Forth. Frequent. 



Remarks. — The posterior foot-jaws, with their extremely long terminal 

 claws, form a prominent character in this species, and one by which it was 

 readily distinguished from the other Copepoda among which it occurred 

 in the shore gathering from Musselburgh. 



Mesochra Maclntoshi, T. and A. Scott (PI. IV. fig. 22). 



1895. Mesochra Maclntoshi, T. and A. Scott, Ann. and Mag. 

 Nat. Hist., ser. 6, vol. xv. p. 53, PI. VI. figs. 1-7. 



Habitat. — In pools near low- water mark on the shore at Musselburgh, 

 Firth of Forth. Not uncommon. 



Remarks. — Though this species is more slender than the typical 

 Mesochra, it is nevertheless in the structure of its various appendages, a true 

 member of that genus. The first pair of swimming feet closely resemble 

 those of Mesochra Lilljeborgii, differing only in the proportionally 

 greater lengtli of the end joint of the inner branches. 



