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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. 
Esterty’s description and figures were drawn up from a single female obtained in the 
Pacific Ocean, and the size is given as g mm. 
5. Paraeuchaeta tonsa. (Giesbrecht). Plate XIV, figs. 8—15. 
Euchaeta tonsa Giesbrecht, 1895, p. 251, pl. IV, figs. 9 & Io. 
Euchaeta tonsa Giesbrecht & Schmeil, 1898, 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, pls. IX & X. 
Euchaeta tonsa Farran, 1908, p. 44. 
Euchaeta tonsa van Breemen, 1908, p. 55, fig. 62. 
Females belonging to this species were found in the plankton collected with the HENnsEen 
vertical net at the following stations. 
Stat. 142 (1500 metres to surface), 1 specimen. — Stat. 148 (1000 metres to surface), I spe- 
cimen. — Stat. 230 (2000 metres to surface), I specimens. — Stat. 276 (750 metres to 
surface), I specimen. 
Paracuchaeta 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. 
Paracuchaeta tonsa appears to have a moderately wide distribution. 
6. Paraeuchaeta gracilicauda nov. sp. Plate XVIII, figs. 9—16. 
Female — length 7 mm. 
Seen from above. The body resembles that of Paraeuchaeta barbata, 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, and 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 cephalothorax, 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 barbata. The distance 
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