i g8 



COPEPODA 



62. Scaphocalanus validus Farran. 

 (PI. VII figs 11 a — b; text-figs 62 a — f.) 



1908. Scolecithrix valida n. sp. Farran, pp. 55—57, pi. V figs 14 — 15, pi. VI fig. 7. 



Description, f £. Size of specimen from Thor St. 183 was 3-95 mm.; anterior division 3-1 mm.; 

 urosome 0-85 mm. Farran's specimens measured 3-8 — 3-95111111. 



The body is more slender, and the head less suddenly raised in lateral view than in S. obtusi- 



frons, but more distinctly so thau in S. globiceps (text-figs 62 a — b). The rostrum is most like that of 



the former species, with the basal part less enlarged and with fairly long, apparently undivided, filaments. 



The lateral corners are slightly produced and rounded (text-fig. 62 c). The genital somite is better produced 



below, and its receptaculum seminis appears more slender than in the preceding species ; the comparative 



length between the abdominal somites and the furcal rami is 

 45, 28, 25, 9 and 17; the furcal rami are 1-5 as long as wide; 

 along the hinder border of somites II— IV a marginal seam 

 with delicate serrations is observed. 



The antennulae do not reach the end of the furca; the 

 segments 24 — 25 are fairly well separated ; "^Esthetasken" are 

 found in segments 8^9, 12, 14 and 19; the segment 10 has a 

 distinct seta, and a proximal seta is found in segments 12 — 14 

 18, and sometimes in segment 15, but never in segment 17; 

 the Sp. of segment 24 is somewhat longer than segment 25. 

 The segment .19 is distinctly r2 as long as segments 8^9 

 and 15, which are of almost equal length; segment 16 is i*a 



Text-fig. 62. Scaphocalanus validus Farr. fO 



a. Head X 33- t>. Rostrum from the right >( 59- 

 c. Genital somite x 33. d. Pes II sin. in anterior as long as 15. The third basipodite of the viandibulae seems 

 view X59- e. Pes III sin. X 59- *■ St. pes II t j , seta£ medially; iu other reS pects the mandi- 



sin. X 150. : J ' l 



bulae as well as the antennae are like those of the preceding 



species. The maxillulae have 7 -|- 2 setae in the L,e, 10 -j- 2 in the Fi I, 2 in Li II, 4 in L,i III and 5 



in the third basipodite; the Ri I has 3 setae, the Ri II 0^ III 5 and the Re has 9 setae. The maxillae 



and maxillipeds are scarcely different from Farran's description. 



The first pair of legs has the Se Re I extending to the base of Se Re II ; in the outer edge of 



the Re III, proximally to the middle, a distinct glandular pore is found, better developed than iu other 



species. The second pair of legs (text-fig. 62 d) is like Farran's fig. 16 PI. V; the Se of Ri I is 



rather short and clumsy, and the St. of Re III has about 35 serrations, some of which are fused at 



their base (text-fig. 62 f) ; the anterior surface of the appendage is minutely granular, and the posterior 



one has, in addition to the usual spines, areas of smaller teeth. No glandular pores were observed. 



The third pair of legs (text-fig. 62 e) has no distinct styliform process at the inner margin of the second 



basipodite, and the slender terminal tooth of the anterior surface of the third basipodite medial to 



the insertion of the endopodite is very short and clumsy ; the posterior surface of the third basipodite 



has a number of short spines in contrast to that of the second foot, which is smooth; in other respects 



this pair is like that of the preceding species. The fourth pair of legs has a long and slender second 



