160 BRITISH COPEPODA. 
lidvwm—they differ very remarkably in the structure of 
the mouth-organs and the first pair of swimming-feet, 
as well as in the minor characters of other parts. 
Altogether, indeed, these organs are much nearer in 
structure to those of the typical Harpacticide than 
are those of the immediately preceding genera. 
1. PELTIDIUM DEPRESsUM (Baird). Pl. LXXII, figs. 1—5. 
Alteutha depressa, Baird. Trans. Berwick Nat. Club, ii, p. 155 
(1845); Nat. Hist. Brit. Entom., p. 216, 
tab. xxx, figs. 1, 2 (1850). 
Carillus oblongus, Goodsir. Ann. and Mag. Nat. Hist., vol. xvi, 
pl. xi, fig. 12 (1845). 
Peltidium purpureum, White. Popular History of British Crus- 
tacea, p. 308, pl. xviii, fig. 4 (1857). 
— —_ P Philippi. Weigmann’s Archiv, p. 131, 
taf. iv, figs. 12, 13 (1839). 
Alteutha purpurocincta, Norman Brit. Assoc. Report, p. 298 
(1868). 
Body ovate; first segment nearly one half the length 
of the body; rostrum large, broad, and prominent ; 
second joint of the anterior antenna (in the female) 
longest; first, third, and fourth nearly equal to each 
other, and about two thirds the length of the second ; 
last five joints very small, all rather densely setose 
(fig. 2). Second foot-jaw (fig. 3) 3-jointed; hand 
ovate, shortly setose on the inner margin. Fifth foot 
not spinous on the sides, but armed at the truncate 
apex with three strong spines, the innermost of which 
is the longest (fig. 4). Caudal lamelle nearly twice as 
long as broad, not tapered to the apex, bearing four 
terminal spines, the innermost the longest, the outer- 
