49 



length of the cephalotkorax^ from the apex of the frontal spine to the base of the genital 

 segment. The first, third, and fourth segments of the abdomen are of about equal length. The 

 second segment is dicidedly longer than the others. The fifth segment is very short. The 

 rostrum is distinctly bïfid at the apex. The mouth organs are considerably modified, and the 

 mandible is without a toothed biting part. The first basal joint of the second maxilliped does 

 not appear to have any tracé of a lamella. The exopodite of the first pair of feet is distinctly 

 three-jointed, and the last joint is furnished with a small spine on the middle of its outer 

 margin. The first joint of the basiopodite of the fourth pair of feet has no bristles on its inner 

 margin. The fifth pair of feet is moderately large and prehensile and has rudimentary endopodites. 

 The right exopodite is two-jointed. The apical portion of the second joint is spiniform and very 

 faintly articulated. The left exopodite is apparently composed of three joints. The apical half 

 of the last joint is spiniform and slightly articulated. The endopodite of the right foot is of 

 moderate size and faintly two-jointed. The apical half is large and triangular in shape. The 

 endopodite of the left foot is short and rod shaped. 



Two specimens were obtained, but one was immature. Length of mature male 5,6 mm. 



I regard Wolfenden's Gaetanus major, to be identical with Giesbrecht's Gaetanus kruppii. 

 Wolfenden's description appeared in a report, 'Plankton of the Faröe Channel', by G. H. Fowlkr, 

 and was read at a meeting of the Zoological Society, London, on February 3rd, 1903. Volume I, 

 part 1 , of the proceedings of the Zoological Society, containing papers read in January and 

 February, is dated June 1903. Gaetanus kruppii is described by Giesbrecht in a report by 

 S. Lo Bianco, published in Mittheilungen aus der Zoologischen Station zu Neapel, 16 Band, 

 1 & 2 Heft, which bears the date April 30, 1903. Giesbrecht's description therefore, appears 

 to be the first that was published. 



The species described by Esterly in 1906, as Gaetanus örevicornis, appears to be the 

 same as Gaetanus major, Wolfenden, and is therefore identical with Giesbrecht's Gaetanus 

 kruppii. The only apparent difference is that Esterly's species possesses a lamella, and Gaetanus 

 major is described as having no lamella on the first basal joint of the second maxilliped. I have 

 examined a number of specimens of a Gaetanus from the deep water of the Faröe Channel, 

 which agree in all points with Wolfenden's Gaetanus major, except that they have a lamella. 

 I think it is extremely probable that the lamella in Wolfenden's preparation had been accidently 

 folded under the joint, and so overlooked. 



Gaetanus clarus Esterly, is the same as the male described above, which I regard to 

 be the male of Gaetanus kruppii. 



Gaetanus kruppii is evidently widely distributed, and is not uncommon in the deep 

 water of the North Atlantic. 



6. Gaetanus latifrons G. O. Sars. Plate X, figs. 10 — 17. 



Gaetanus latifrons Sars, 1905(0), p. 11. 

 Gaetanus liolti Farran, 1905, p. 33, pi. VI, figs. 1, 12. 

 Gaetanus longispinus Wolfenden, 1905, p. 7, pi. III. 

 Gaetanus latifrons Pearson, 1906, p. 14. 



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SIBOGA-EXPEDITIE XXIX a. 7 



