NO 5.] ACCOUNT OF THE SPECIES. 25 



the base by a very narrow fissure. Each of the lateral halves terminates in 

 a very acute point, and exhibits a row of about 7 small sub-marginal 

 denticles. 



The colour in the living state of the animal, according to notes of 

 Dr. Nansen, is bright red, with somewhat darker eyes. 



Occurrence. Several specimens of this interesting Amphipod were taken 

 on the 23rd and 24th April, 1894, at about the 80th degree of latitude, clinging 

 to the sounding-line, the latter having been lowered to a depth of between 500 

 and 1000 metres. As in every instance the specimens were found on the lower 

 part of the line, at only a short distance from the water-bottle, it must be 

 assumed that they in reality occurred in the deepest strata, near the bottom. 



A single specimen was also found in a sample taken a little farther south, 

 on the 23rd March same year, the tow-net having been lowered to 300 meters. 

 Finally, the same form occurred in a sample taken on the 4th February, 1896, 

 in a place lying much farther west, and north of the 85th degree of latitude, 

 the tow-net having in this instance been lowered to only 100 130 metres. 

 By far the greater number of the specimens caught here were, however, 

 of rather small size, only 2 of them being apparently fully grown. From 

 its occurrence in this place, it must be inferred that this Amphipod is 

 not strictly a bottom-form, but, like the species of the genus Pseudalibrotus, 

 sub-pelagic in habits, though at times descending to very great depths. 



Distribution. Off the Lofoten Islands, taken by the aid of the bow-net 

 ('nasse'), in a depth of 1095 metres (Expedition du Prince de Monaco). 



Gen. Pseudalibrotus, Delia Valle. 



Syn: Alibrotus, G. 0. Sars (not M.-Edw.). 



Remarks. This genus was proposed by Signor Delia Valle in his great 

 works on the Gammarids of the Gulf of Naples, to include the well-known 

 arctic species Anonyx littoralis of Kroyer, which I had erroneously referred 

 to the genus Alibrotus of Milne-Edwards. In addition to the above-named 

 arctic form, 2 new species of this genus have been recently described by 

 the present author from the Caspian Sea, both belonging to the collection 

 of Dr. 0. Grimm. I have now to report 2 additional species, found 

 in the material collected during Nansen's North Polar Expedition, both of 



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