292 MR. G. p. FAHRAN ON COPEPODA 



as wide, and the fuvca, which is slightly longei' and more slender. 

 They agree well, on the other hand, as far as the text and figures 

 go, with Giesbrecht's description of G. tenuis, though that writer 

 makes no mention of the ventral hook on the genital segment. 



The length, r05 mm., is slightly greater than that given by 

 Giesbrecht, viz. "9 mm. The length of the cephalothorax in the 

 middle line, dorsal view, is '64 mm., of the abdomen and furca 

 •41 mm., the proportional lengths of abdominal segments and 

 furca being 14 : 8 : 18. Measured along the ventral margin the 

 proportions are more nearly 12 : 10 : 17. The pigment of the 

 eye-apparatus shows very distinctly thiough the body as of a blue- 

 green colour. 



The second antenna (PI. XII. fig. 9) bears a long spine on the 

 first basal joint and a much shorter spine, one-third as long, on 

 the second basal joint. The inner margin of the second basal ends 

 distally in two strong teeth. The terminal claw of the second 

 antenna is just equal to the spine of the second basal. 



The swimming-feet have no distinctive features, except that the 

 terminal spine of the exopodite of the second foot is very slightly 

 cui^ved. 



Six specimens were found in two gatherings. 



Distribution. Indian Ocean and Tropical Pacific. 



CoRYC^us DUBius, sp. n. (PI. XII. fig. 7, PL XIV. figs. 5-9.) 



In the Maldive collections Dr. Wolfenden (11) obtained a 

 specimen of Gorycmus, which, following Dahl's table, ought to be 

 C. amazonicas, but, as he remarks, without figures it is impossible 

 to refer it with ceitainty to that species. In the Christmas 

 Island collection there occurred one specimen of a female, 

 described below under the name of C. duhius, which may well be 

 the same species as that to Avhich Dr. Wolfenden refers, but 

 again the absence of figures precludes certainty. The particulais 

 given by Dr. Wolfenden — namely, the size, 1*0 mm., and the 

 proportionate lengths of abdomen and furca 7:8: 9 — come very 

 near '97 mm. and 21 : 23 : 28, the corresponding measurements 

 in my specimen. The lateral prolongations of the third and 

 fourth thoracic segments are short in both specimens. In 

 Wolfenden's specimen, however, the spine on the second joint of the 

 second antenna is said to be " not more than half the length of 

 that of the 1st basal, and shorter than the distal hook," but in 

 mine the spine in question is just one-third as long as that on 

 the 1st basal and is distinctly longer than the distal hook. 



Cleve (4) has described a species, C. erythrceihs § , from the 

 Red 8ea, Avhich is very closely allied to both the above-mentioned 

 forms, but if his description be taken as accurate it must be 

 distinct. The female genital segment has seta? on the genital 

 openings and a ventral hook, the endopodite of the 4th foot has 

 two setce, and the furca is moderately long. The size -88- '94 mm. 

 is slightly less than that of G. cliMas. The proportions of the 



