78 COPEPODA 



5 setae. The Ri has 13 setae as the Ri I has 3 Sa -f 1 Sp, and the Re has only 10 setae. The 

 posterior seta of the first lobe of the maxilla is at least 3 times as long- as the lobe itself. In the 

 maxillipeds the third basipodite is about 1-3 as long as the second, and three times as long as the endo- 

 podite. The fourth lobe possesses in addition to the usual 3 hairs a short hairy sensory process. In 

 contrast to Sars' figure the distance between the Si 2 and Si 3 is 2 - 5 as long as the distance between 

 the Si 1 and 2. 



The first pair of legs has the Se Re I just extending beyond the tip of Re II. On the 

 anterior surface of Re II, near the lateral margin, 1 — 2 minute pores are often observed, and at the 

 outer margin of Re III, somewhat posteriorly, just in the middle, a pore, placed on a minute process 

 surrounded by delicate hairs, is found. The pes II has a fairly distinct articular surface between 

 Re I — II anteriorly, but posteriorly it is partly wanting in contrast to pes III— IV, in which it is well 

 developed. The terminal spine has 40—50 well separated teeth (fig. 3 a). On the anterior surface of 

 the Ri III the usual glandular pore surrounded by delicate hairs is found in the last three pair of 

 legs; the usual glandular pores at the base of Se Re I— III in the three last pair of legs are not seen, 

 but they are certainly represented by a number of pores which, as shown in fig. 3 a, in the arrange- 

 ment provides an important character for this species; the "pore" is formed by a chitiuous ring, in 

 the middle of which a generally longitudinal split is seen. In the Re I a single pore and in Re III 

 three are found in pes II — IV, but in Re II a single is found in pes IV, but 2 in pes II — III. 



The lateral outline of the labrum is like Sars' figure PI. XV, and scarcely different from 

 Aetidius. The anterior surface of the labrum has, in addition to the usual marginal row of setae 

 which are fairly slender in the middle and more like granules laterally, in the middle a transverse 

 row of laterally shorter setae, and in front on each side a group of short setae. 



The oral surface of the labrum is rather characteristic (fig. 3 b). In front of the chitinous 

 transverse bar behind the median central spot Nr. 3, a transverse row of short setae is found; around 

 and behind the median spot 4 (S*) short setae are placed in transverse rows. The skin is everywhere, 

 especially posteriorly, minutely granular. The lateral longitudinal series consists as usual of 5 groups; 

 the two first groups are placed somewhat longitudinally, are distinctly longer than wide, and consist 

 of short spinules, most like granules; the groups 3 — 5 are, in contrast to the two first, less well sepa- 

 rated, and consist of an inner row of longer and an irregular, outer group of scattered shorter hairs. 



The lamina labialis (fig. 3 c) is in the shape of the dentations somewhat different from that of 

 Ch. obtusifrons (fig. 2 a), and it is almost smooth. The arrangement of the groups of hairs in front of 

 and behind the lamina labialis I refer to Ch. obtusifrons. About the arrangement of the series of 

 bristles on the labial lobes, the fig. 3 d will give an impression. 



fo*. Size: Specimen from Thor St. 99 1904 measured 3-66 mm., anterior division 2"65 mm. 

 urosome ror. mm. 



The body seems to be more slender than figured by Sars; the anterior division is 2 - 6 as long 

 as the urosome; the fifth thoracic tergite is well distinguished. The first abdominal somite is some- 

 what assymmetric, and the genital pore is found on the left side; the second somite is three times 

 as long as the first; the f ureal branches, which are almost twice as long as the anal somite, are i-6 

 as long as wide. 



