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Gaetanus latifrons Farran, 1908, p. 36. 



Gaetanus latifrons van Breemen, 1908, p. 39, fig. 43. 



One specimen of Gaetanus latifrons, was obtained from the plankton collected with the 

 Hensen vertical net at Station 276 (750 metres to surface). This species is easily distinguished 

 from the other knovvn Gaetanus, by the peculiar form of the forehead and cephalic spine, when 

 seen in lateral view. 



The antennules extend beyond the furca by at least three joints. The frontal spine is 

 prolonged and when viewed laterally, is seen to be slightly curved upwards. The forehead seen 

 from the side, is wide and truncate, with a slight crest extending from the base of the spine 

 to beyond the middle of the fontal margin. The spines of the last thoracic segment extend 

 beyond the middle of the genital segment. The combined length of the abdomen and furca 

 is equal to one-third of the total length of the cephalothorax, from the apex of the cephalic 

 spine to the base of the genital segment. The genital segment is nearly as long as the combined 

 length of the next three segments. The third segment is distinctly smaller than any of the 

 others. The rostrum is distinctly bifid at the apex but the points are not symmetrical. The 

 lamella on the base of the first joint of the second maxilliped appears to be quite pointed. 

 The preparation made from the 'Siboga' specimen is slightly distorted, and the lamella is folded 

 over the surface of the joint. The exopodite of the first pair of feet is distinctly three-jointed, 

 and the first joint is furnished with an outer-edge spine. The first joint of the basiopodite of 

 the fourth pair of feet, is furnished with a number of moderately long and strong bristles on 

 its inner distal angle. Length of female, 5,4 mm. 



There appears to be no difference between the specimen obtained from the Malay 

 Archipelago, and the figures given by Farran. 



Gaetanus latifrons has been recorded from the North Atlantic Ocean by Sars, and 

 almost at the same time by Farran and Wolfenden. Farran described it as Gaetanus Itolti, 

 and Wolfenden as Gaetanus longispinus. 



7. Gaetanus hamatus nov. sp. Plate IX, figs. 16 — 22. 



Female — length 5,4 mm. 



Seen from above, the body is moderately robust with a broadly rounded forehead. Viewed 

 laterally, the cephalic spine is seen to be very small, and similar to that of Gaetanus kruppii. 

 The spines of the last thoracic segment are very short and stout. The spines are pointed at 

 almost a right angle, in the dorsal direction from the segment. 



The abdomen is composed of four segments. The combined length of the abdomen and 

 furca is equal to one-third of the total length of the cephalotJiorax, from the apex of the 

 cephalic spine to the base of the genital segment. The genital segment is slightly longer than 

 the second segment. The third segment is rather smaller than any of the others. The anal 

 segment is as long as the genital segment. The furcal joints are slightly longer than broad, 

 and are fully half as long as the anal segment. 



The rostrum is small and the apex is distinctly bifid. 



The antennules are twenty-four-jointed, and extend beyond the furca by the last three joints. 



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