COPBPODA. 
15 
Metridia gerlachei. 
Metridia gerlacliei, G-iesbrecht, ‘Belgica’ Report, p. 27. 
? 3*5-3 *8 mm., very variable in size, occasionally a little larger and often smaller, 
but the average of size of examples in the ‘ Discovery ’ and ‘ Gauss ’ collections is 
rather less than that given by Giesbrecht for the ‘ Belgica ’ specimens. The eephalo- 
thorax is one and a half times as long as the abdomen, head separate from first thoracic 
segment, last segment with rounded margins. The abdomen has the proportional 
length of its three segments as 9 (genital) : 6 : 4 (anal), and the furca is one-fifth longer 
than the anal, and three times as long as broad. It is divided into two portions by the 
outer marginal bristle, of which the proximal is twice the length of the distal. 
The shape of the head and thorax is in this species characteristic, the back being 
extremely gibbous, and the head with very bold curve, which makes it easily recognis¬ 
able at sight from any other species of this genus. The anterior antennae are com¬ 
paratively short and do not reach beyond the genital openings. The first and second 
segments are coalesced ; the eighth, ninth, tenth, eleventh, have only faint indications 
of separation ; the thirteenth and fourteenth joints are not so clearly divided as the 
others. There are strong teeth on one, two, three, five, seven (one each), those of 
the third, fifth, seventh joints the strongest, and directed straight forwards. The 
sesthetasks are numerous. 
The endopodites of the second pair of feet have the usual excavation and hook 
process on the first segment, but in this species the inner hook is exceedingly strong. 
In the fourth pair the end saw is only two-fifths of the whole length of the Re 3 
(shorter than in Giesbrecht’s examples). 
The fifth pair consists on each side of three segments, but the distal segment is 
more or less completely divided into two, the division however is not complete. The 
two basal joints are of about the same length and breadth, each as broad as a little 
over half the length. The third joint, however, is not more than four-fifths as long as 
the basals, and only half the breadth. The second joint bears one short distal bristle, 
the last joint one outer marginal bristle in the proximal half, and three distal bristles, 
of which the innermost is the longest and thickest, the outermost the shortest. 
Metridia princeps. 
(Plate III., figs. 3, 4, 5.) 
Metridia princeps, Giesbrecht, Atti Line. Rend., Ser. 4, v. 5, p. 24. 
„ ,, ,, Fauna n. FI. Neap. XIX., p. 340. 
,, „ „ Farran, Ann. Rep. Fish. Ireland 1902-03, PI. II. App. II. (1905). 
? Metridia macrura, Bars, Bull, du Mus. Oceanog. Monaco, 1905, no. 40, p. 7. 
Though only one example of this species occurred in the £ Discovery ’ collection, it 
was frequent in the ‘ Gauss ’ collection, not only at several Atlantic stations, but also 
