E21 
Females apparently identical with the above species, were obtained from the plankton 
collected with the HeEnsrEn vertical net at the following stations. 
Stat. 118 (900 metres to surface), 3 specimens. — Stat. 141 (1500 metres to surface), 4 spe- 
cimens. — Stat. 143 (1000 metres to surface), 4 specimens. — Stat. 185 (1536 metres to 
suface), 3 Specinrens: —— Stat. 203 (1500 metres to surface), 4 specimens. — Stat. 276 
(750 metres to surface), 4 specimens. 
The genital segment of the ‘Siboga’ specimens, is equal to the combined length of the 
second and third abdominal segments. The fifth pair of feet is composed of two free joints 
attached to a basal part. The apical joint of one foot is furnished with two setae, and the 
other with one only. (Plate XX XVII, fig. t1). Length 1,9 mm. 
The female fifth pair of feet of MWetrzdia curticauda, a species closely related to Metrzdia 
brevicauda, has three free joints and a basal part. 
Metridia brevicauda has been recorded from the Atlantic and Pacific Oceans. 
3. Metridia macrura G. O. Sars. Plate XX XVIII, figs. 8—11. 
Metridia macrura Sars, 1905 (0), p. 7. 
A single female agreeing with the preliminary description of the above species, was 
found in the plankton collected with the HENSEN vertical net at Station 230, 2000 metres to 
the surface. Length 10,5 mm. 
The furcal joints are nearly three times the length of the anal segment. The joints are 
twelve times longer than broad. The fifth pair of feet is very similar to that of the female of 
Metridia princeps. 
4. Metridia princeps Giesbrecht. Plate XXXVIII, figs. 1—7. 
Metridia princeps Giesbrecht, 1889, p. 24. 
Metridia princeps Giesbrecht, 1893, p 340, pl. 33. 
Metridia princeps Giesbrecht & Schmeil, 1898, p. 107. 
| Metridia princeps 1. C. Thompson, 1903, p. 24, pl. VI, figs. 3 & 4. 
Metridia princeps Cleve, 1904, p. 192. 
Metridia princeps Sars, 1905(0), p. 2. 
Metridia princeps Farran, 1905, p. 43. 
Metridia princeps Pearson, 1906, p. 24. 
_ Metridia princeps Esterly, 1906, p. 69, pls. 11, 13 & 14. 
Metridia princeps Farran, 1908, p. 61. 
Metridia princeps van Breemen, 1908, p. I10, fig. 127. 
Nine females and six males were obtained from the plankton collected chiefly with the 
HENSEN vertical net at the following stations. 
Stat. 118 (900 metres to surface). — Stat. 128 (700 metres to surface). — Stat. 141 (1500 
metres to surface). — Stat. 148 (1000 metres to surface). — Stat. 185 (1536 metres to 
surface). — Stat. 203 (1500 metres to surface). — Stat. 217 (horizontal cylinder). — Stat. 
243 (1000 metres to surface). 
The furcal joints of both sexes are twice as long as the anal segment, and five times 
longer than broad. Length, female 7,9—8,8, male 8,3 mm. 
E21 
SIBOGA-EXPEDITIE XXIXa@. 16 
