. Copepoda. Calanoida; Copepoda. COPEPODA 147 Ri of the maxillulae and the presence of a Se Re I pes I. The two genera are very nearly related, but as the five species of Undeuchate form a very natural group I prefer to refer this species to 42. Chirudina abyssalis n. sp. (PI. V figs 5 a—f; text-figs 40 a—c). Description. 1% Size of specimen from Thor St. 183 was 5-4 mm.; anterior division 4-3 mm.; urosome n mm. The head is gradually rounded in front, without any crest; the rostrum is rather short, but strong, directed downwards and slightly backwards (text-fig. 40 a). The cephalot
. Copepoda. Calanoida; Copepoda. COPEPODA 147 Ri of the maxillulae and the presence of a Se Re I pes I. The two genera are very nearly related, but as the five species of Undeuchate form a very natural group I prefer to refer this species to 42. Chirudina abyssalis n. sp. (PI. V figs 5 a—f; text-figs 40 a—c). Description. 1% Size of specimen from Thor St. 183 was 5-4 mm.; anterior division 4-3 mm.; urosome n mm. The head is gradually rounded in front, without any crest; the rostrum is rather short, but strong, directed downwards and slightly backwards (text-fig. 40 a). The cephalothorax, which is moder- ately slender and slightly attenuated towards the front part as well as towards the end, is about 2-5 as long as wide; the first thoracic tergite is, at least dorsally, well separated from the head; the fifth somite, which is well separated in front, is laterally not produced, and has evenly rounded corners (fig. 5 a). The anterior division is about four times as long as the abdomen. The genital somite, which is a little wider than deep and as deep as long, is in dorsal outline almost symmetrical; the ventral surface is anteriorly rather suddenly produced and posteriorly gradu- ally sloping; the genital area is in ventral view seen to be somewhat different from that of the preceding species. The genital somite possesses, dorsally, along hinder margin, short hairs, and ventrally tufts of longer hairs; the fol- lowing somites are more and less hairy, the hairs being longest dorsally and ventrally. The caudal rami are about as long as wide; the terminal setae are distinctly shorter than the abdomen and about three times as long as the Si. The antennulae extend to the end of the caudal rami; the measurements are very like those of the preceding species. The exopodite of the antennae is r6 as long as the endopodite; the second segment of the endopodite has 8 setae in \Ji and 7 in L,e; the first segment of the exopodite, which is one third as long as the se
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Keywords: ., bookauthorhansenhj, bookcentury1900, bookdecade1910, bookyear1915
