7° 
The males aré easily separated by the structure of the left exopodite of the fifth pair 
of feet. The second joint is only slightly produced at its inner distal angle. The third joint is 
short and rudimentary. In true Awchaeta the third joint is long and spiniform. 
Twelve species belonging to this genus were found in the plankton collected by the 
‘Siboga’. Nine of the species appear to be unknown, but four of them are males which may 
prove to be identical with some of the females now recorded. 
1. Paraeuchaeta barbata (Brady). Plate XVIII, figs. 1—8. 
Euchaeta barbata Brady, 1883, p. 66, pls. XXII, figs. 6—12. 
Euchaeta barbata Farran, 1908, p. 40, pl. Ill, figs. 13 & 14. 
Five females of this form, which appears to be identical with Fuchaeta barbata Brady, 
were found in the plankton collected with the HENSEN vertical net at Station 230, 2000 metres 
to the surface. 
The figure illustrating the outer-edge spines on the exopodite of the second pair of feet 
given in this report, agrees very well with the figure given by Brapy, and also by Farran. 
The outer-edge spine on the second joint is long, and reaches to about midway between the 
base and apex of the first outer-edge spine on the third joint. The second outer-edge spine 
on the third joint is very stout, and extends distinctly beyond the base of the third outer-edge 
spine. The sinus at the base of the second outer-edge spine on the third joint is very deep. 
The second inner seta on the furcal joints is long, but the appendicular seta is longer than it. 
Length of female 7,5 mm. | 
The form described and figured by Sars in ‘Crustacea of Norway’, although resembling 
Paracuchaeta barbata very closely, appears to be distinct. Sars states that the legs scarcely 
differ in structure from those of Paraeuchaeta norvegica. Vhe proportional lengths of the outer- 
edge spines on the exopodite of the second pair of feet of Paraeuchaeta norvegica, are very 
distinct from that shewn in Brapy’s figure. . 
Brapy’s specimen was obtained in the South Atlantic to the east of Monte Video. 
Farran records it from the North Atlantic off the West Coast of Ireland. 
2. Paraeuchaeta bistnuata (Sars). Plate XVI, figs. 10—17. 
Euchaeta. bisinuata Sars, 1907 (a), p. 12. 
Euchaeta bisinuata Farran, 1908, p. 45, pl. Ill, figs. 17—19; pl. IV, fig. 4. 
Females similar to the form identified and figured by G. P. Farran as Fuchaeta bzisz- 
nuata Sars, were found in the plankton collected at the following stations in the area investigated 
by the ‘Siboga’. 
Stat. 117°, I specimen. — Stat. 230 (HENSEN vertical net 2000 metres to surface), 2 speci- 
mens. — Stat. 243 (HENSEN vertical net 1000 metres to surface), 1 specimen. — Stat. 252, 
I specimen. — Stat. 276 (HENSEN vertical net 750 metres to surface), I specimen. 
Paracuchaeta bisinuata is easily recognised by the peculiar arrangement of the pro- 
tuberance on the ventral surface of the genital segment. The protuberance is divided into three 
lobules, and the two anterior ones are paired. The outer-edge spine on the second joint of 
7O 
— 
