/ - 



spine on the third joint. The second outer-edge spine on the third joint does not reach the 

 base of the third outer-edge spine. 



The second inner seta on the furcal joints is very long but the appendicular seta is 

 longer than any of the others. Length of female 10 mm. 



Esterly's description and figures were drawn up from a single female obtained in the 

 Pacific Ocean, and the size is given as 9 mm. 



5. Paraettchaeta tonsa. (Giesbrecht). Plate XIV, figs. 8 — 15. 



Euchaeta tonsa Giesbrecht, 1895, p. 251, pi. IV, figs. 9 & 10. 



Euchaeta tonsa Giesbrecht & Schmeil, 1S98, p. 40. 



Euchaeta tonsa Cleve, 1904, p. 190. 



Euchaeta tonsa Sars 1905 (a), p. 5. 



Euchaeta tonsa Farran, 1905, p. 35. 



Euchaeta tonsa Pearson, 1906, p. 17. 



Euchaeta tonsa Esterly, 1906, p. 64, pis. IX & X. 



Euchaeta tonsa Farran, 1908, p. 44. 



Euchaeta tonsa van Breemen, 190S, p. 55, fig. 62. 



Females belonging to this species were found in the plankton collected with the Hensen 

 vertical net at the following stations. 



Stat. 142 (1500 metres to surface), 1 specimen. — Stat. 14S (1000 metres to surface), 1 spe- 

 cimen. • Stat. 230 (2000 metres to surface), 1 specimens. — Stat. 276 (750 metres to 

 surface), 1 specimen. 



Paraeuchaeta tonsa is easily recognised by the bluntly pointed last thoracic segment, 

 and by the large projection on the genital segment when the female is viewed from the side. 

 The outer-edge spine on the second joint of the exopodite of the second pair of feet, is longer 

 than any of the other outer-edge spines. It reaches to about midway between the base and 

 the apex of the first outer-edge spine on the third joint. The second inner seta on the furcal 

 joints is much longer than any of the others. Length of 'Siboga' specimens 7 mm. 



Paraeuchaeta tonsa appears to have a moderately wide distribution. 



6. Paraetuhaeta gracilicauda nov. sp. Plate XVIII, figs. 9 — 16. 



Female — length 7 mm. 



Seen from above. The body resembles that of Paraeuchaeta óaróata, except that it is 

 distinctly contracted in the middle of the cephalic segment, and the rostrum is directed down- 

 wards. The posterior margin of the last thoracic segment appears slightly angular when seen 

 in lateral view. The epistome is hirsute, ancl the tuft of hairs on the last thoracic segment is 

 well developed. 



The abdomen is very slender. The combined length of the abdomen and furca is 

 contained one and three-fourth times in the total length of the cep halothorax, from the frontal 

 prominence to the base of the genital segment. The genital segment is slightly shorter than 

 the combined length of the second and third segments. It is symmetrical in outline, and the 

 lobules at the genital opening are similar to those of Paraeuchaeta óaróata. The distance 



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