COPEPODA. 15 



METRIDIA GERLACHEI. 

 Metridia gerlachei, < < iesbreekt, 'Belgiea' Report, p. -2~. 



9 3 '5-3 "8 mm., very variable iii 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 cephalo- 

 thorax is one and a half times as long as the abdomen, head separate from h'rst thoracic 

 segment, last segment with rounded margins. The abdomen has the proportional 

 length of its three segment ~ as 9 (genital) : fi : 4 (anal), and tin- i'urca i- one-lift h longer 

 than the anal, and thivr limes as long as bmad. It is divided into two portions by the 

 outer marginal bristle, <>f 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 easilv recov.ni.~- 

 able at sight from any other species of this genus. The anterior antenna' 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, rive, seven (one cadi), 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 fie 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 shorte.-t. 



MKTKIUIA PRIXCKPS. 

 (Plate III., figs. 3, 4, 5.) 



Sfetridia princeps, Giesbrecht, Atti Line. Ki/ml.. SIT. I. v. ."i. p. i'i. 

 Fauua 11. !'!. Xrap. XIX.. p. ::in. 



ravran, Ann. l!r|>. Fir-h. Iivlaml I'.IOL' OS, PI. II. \[>\<. II. < l'J05). 



ilii/ nitii-rtirii, Sal's, Bull, iln Mils. Ocuimog. Monaco, I'.HI.'P, no. In, p. 7. 



Though only one example of this species occurred in the 'Discovery' collection, it 

 was fre<|iient in the 'Gauss' collection, not only at several Atlantic stations, but also 





