﻿COPEPODA 



75 



I have preferred to exclude other species of somewhat doubtful position, as well as to let Wolf- 

 enden's genus Mcsjiudcuchata go out. Though the different species of Etcchirella differ from 

 each other in several important features, I think the genus is a quite natural one, as it is not .only 

 characterized by the structure of the antennae and niaxillulae, but also by the jiresence of a glandular 

 pore at the base of Se I Re II pes II— IV (cf. Cliiridiits], which is wanting in the penultimate stao-e. 

 In Eiicli. rostrata, i/irssiiici/sis, maxinia and brtiiiiiida a glandular pore is wanting in the first outer 

 segment in the second pair of legs, but in E. curticmida and intermedia it is wanting in the third 

 and fourth pairs of legs as well. In addition to the generally accepted specific characters, good ones 

 are found in the structure of the oral surface of the labrum, in the uumlxjr of bristles of the exopodite 

 of the niaxillulae in the males, and in the marginal hairs of the .second basipoditc of the fourth 

 pair of legs. 



15. Aetidius armatus Boeck. 

 (PI. II fig. I a-d; text-fig. 16). 



1872. Pseuilocalanus annatu.s 11. sp. Bocck, p. 3S. 



1SS3? .\etidius aniii 



1S92. nee. — — 



I.Sg^. pars. — — 



189S. pars. -- — 



1901. — — 



1902. — — 



1902. — — 



1903. — — 

 1903. — — 



1903? — — 



1904. Aetidius teniiirostris n. sp. Wolfenden, pp. 116 117. 



— armatus Boeck. Farraii, p. 31. 



— " — Esterly, p. 145, fij^'s. 14 a b. 



— — — Th. Scott, p. 222. 



— — — Pearson, p. 11. 



— — — V. Bremen, p. 30 fig. 30. 



— — — Farran, p. 28. 



— — — Pesta, p. 23. 



— — — A. vScott, pp. 37 38, pi. IV, figs 



14-25. 



— — — Steuer, pp. 23 — 24. 



— — — Wolfenden, p. 209, text-fijj. 4. 



— — — Farran, pp. 81— 82. 



Description. ?. Size of specimen from Ingolf St. 47, 1-93 nun.: anterior division (head • soni. 

 thor. I 0-920; .somite II — V 0-575) i'495; urosome 0-437 mm. 



The head is as figured by Sars etc. vaulted in a characteristic way without frontal keel, and 

 the rostrum has two pointed branches without liasal tubercle. The genital somite, wliich is both wider 

 and deeper than long, has a receptaculum seminis (text-fig. 16) which is distinctly dif- 

 ferent from that of A. GiesbrecJifii Cleve 1904 (synonymous with A. iiicdilerraiieiis 

 Steuer 1910), as seen by comparing figs i a— b with Giesbrechts fig. 9 Taf. 36; the 

 vulva (fig. lb) is also somewhat different from Giesbrecht's fig. 8. 



The measurements of the autenmilae are distinctly different from those gi\cu 

 by Giesbreclit, as the segment 23 is shorter than 22, and as segment 24^25 is 

 respectively 1-4 and 1-5 as long as segment 8~9 and 2 (not 2 and 2-5). The antennae 

 differ from Sars' as well as from Giesbrecht's figures by the small process on which 

 the proximal seta of Re II is placed. The other mouth ajipandages show some dil- 

 ferences from Sars' figme.s, Init not in any feature worth to be mentioned from Gies- 

 brecht's description. 



The pes I differs from G i esbrecli t 's deseripti<Mi (fig. ro) b\- the second basipodite, which has 

 no setae exteriorlv and distally, and by the third one, which has no spinous area laterall\- and anteriorly. 



Text-fig. 16. 



Aitiiiius iiimatus 



Boeck. 



Abdomen ill left 



view X 57- 



