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 folio wing 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, 1 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 Faröe 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 Megacalanus princeps, 

 and subsequently withdrew the specific name in favour of bradyi, under the impression that 

 Brady's Calanus princeps belonged to the same genus. Farran and van Breemen have used 

 Sars specific name longicomis, as it was given prior to the substitution of the new name by 

 Wolfenden. Brady's Calanus princeps apparently belongs to the new genus described below 

 rather than to Megacalanus, and the name originally given by Wolfenden must necessarily 

 be restored. 



Genus Bradycalanus nov. 



In general appearance, this new genus resembles Megacalanus 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 Calanus. The generic description of 

 Bathycalanus Sars i905(«), states that the exopodites of the first feet are two-jointed, and in 

 this important point it differs from Bradycalanus. The forehead has no tracé of a dorsal crest 

 which distinguishes Megacalanus and Bathycalanus from Wolfenden's Heterocalatius, a name 

 by the way that has been previously used in the Gulf of Guinea report for a new Calanoid 

 that afterwards became a synonym of Pseudodiaptomus. So far, only the female of Bradycalanus 

 is known. 



I think that it is probable that Brady's Calanus princeps belongs to this genus rather 

 than to Bathycalanus or Heterocalanus, but I do not regard it as identical with the species 

 upon which this genus is founded. 



1. Bradycalanus typieus 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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