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but only one of them was mature. The length of the mature female was 9,5 mm. exclusive 
of the caudal setae. It was found at the following stations. 
Stat. 148. HENSEN vertical net, 1000 metres to surface, 2 specimens. 
Stat. 185. HENSEN vertical net, 1536 metres to surface, 2 specimens. 
Stat. 243. HENSEN vertical net, 1000 metres to surface, I specimen. 
I have been unable to detect any difference between the original description given by 
WoLFENDEN from the North Atlantic specimen, and those from the area investigated by the 
‘Siboga’. I have also examined specimens from the deep water of the Farée Channel, and find 
that they are identical with the figures given on plate I of this report. 
As already stated WoLFENDEN originally described the species as MWegacalanus princeps, 
and subsequently withdrew the specific name in favour of éradyz, under the impression that 
Brapy’s Calanus princeps belonged to the same genus. FarRAN and vAN BREEMEN have used 
Sars specific name /oxgicornzs, as it was given prior to the substitution of the new name by 
WOLFENDEN. Brapy’s Calanus princeps apparently belongs to the new genus described below 
rather than to J/egacalanus, and the name originally given by WoLFENDEN must necessarily 
be restored. 
Genus Bradycalanus nov. 
In general appearance, this new genus resembles JZegacalanus Wolfenden, but is at once 
distinguished from it by the densely plumose spines on the apex of the first maxillipedes, 
and by the absence of the prominent hook on the anterior surface of the second joint of the 
basiopodite of the first feet. The endopodites and exopodites of the five pairs of feet are three- 
jointed. The last joint of the exopodites of the second, third, and fourth feet are furnished with 
three spines on the outer margin instead of two as in Ca/anus. The generic description of 
Bathycalanus Sars 1905 (a), states that the exopodites of the first feet are two-jointed, and in 
this important point it differs from LBradycalanus. The forehead has no trace of a dorsal crest 
which distinguishes A/egacalanus and LBathycalanus from WoL¥FENDEN’s Ffeterocalanus, a name 
by the way that has been previously used in the Gulf of Guinea report for a new Calanoid 
that afterwards becamie a synonym of Pseudodiaptomus. So far, only the female of Bradycalanus 
is known. 
I think that it is probable that Brapy’s Calanus princeps belongs to this genus rather 
than to Lathycalanus or Heterocalanus, but 1 do not regard it as identical with the species 
upon which this genus is founded. 
1. Bradycalanus typicus nov. sp. Plate I, figs. 1—11. 
Female — length 9 mm. 
The head is distinctly separated from the first thoracic segment. It is considerably 
contracted in front and produced slightly into a rounded knob as seen from the dorsal aspect, 
fig. 1. The fourth and fifth thoracic segments are completely separated. The fifth thoracic 
segment is produced posteriorly and ends in distinct points. When viewed from the side the 
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