CRUSTACEA MAI,ACOSTRACA. IV. 



C. Geographical and bathymetrical Distribution. 



It is an interesting fact, that in the cold deep-sea area, with depths from about 300 to 1309 fathoms 

 and the temperature at the bottom below zero, only 9 species have been taken, and that not a 

 single species among these is exclusively limited to that area. Among these species two, viz. 

 Leucon fulvus G. O. S. and L. Nathorstii Ohlin, have in that area only been taken at Stat. 126, 293 fath., 

 temp. 4- 0.5, thus near the limit of the area; L. Nathorstii has also been found in Davis Strait, 318 fath., 

 temp. 3.9, while L. fulvus was secured at six stations in Davis Strait, in depths from 88 to 1199 fath., and 

 temperature from 1.6 to 3.9, and besides in low water at Iceland, etc. Leucon spinulosus n. sp. has been taken 

 south of Jan Mayen in 1003 fath., temp, 4 1.0, but besides at three deep stations in the warm area, in 582 

 to 1435 fath., temp. 3.3 1.5. Campylaspis intermedia n. sp. has been taken south of Jan Mayen, 371 fath., 

 temp. -4- 0.4, and besides in Davis Strait, 318 fath., temp. 3.9. Leptostylis vittosa G. O. S. has been gathered 

 two times in the cold area, in 293 and 471 fath., temp. 4- 0.5 and 4 0.6, but besides in the warm area 

 in Davis Strait, 318 fath., temp. 3.9, in low water at Iceland, furthermore south and north of Iceland in 

 depths between about 18 and 194 fath. Leptostylis longimana G. O. S. has been taken five times in the cold 

 area, 471 762 fath., temp. 4 0.6 4 0.9, but is was also secured at two typical stations in the warm area 

 (and at several places in the North Sea, south-east of our area). Diastylis Rathkii Kr. was taken in the cold 

 area, 471 fath., temp, 4 0.6, and several times in the warm area down to 420 fath., and in lower water. 

 Diastylis spinulosa Heller was gathered once in the cold area, 537 fath., temp, 4 0.7, but besides in Davis 

 Strait in depths from 48 to about 200 fath. and the bottom temperature above zero. Diastylis polaris G. O. S. 

 (= D. stygia G. O. S.) may be called a typical inhabitant of the cold area, and the "Ingolf" captured it at 



ten such stations in depths from 371 to 1309 fath., temp. 4- 0.4 ^ 1.1, but the same ship gathered also 



specimens in the warm area, in Davis Strait, 582 fath., temp. 3.3, and Caiman records it from many stations 

 off America between Lat. 4iVs N. and Lat. 3725' N., depths generally from 1149 to 1769 fathoms. It is 

 interesting that, while 8 species of Tanaidacea and 15 species of Isopoda are in my earlier "Ingolf "-papers 

 recorded as only taken in the cold deep-sea area, not a single species of Cumacea is limited to that area. 



We find also considerable differences as to bathymetrical distribution between Tanaidacea and Iso- 

 poda on one hand and the Cumacea on the other. At the deepest "Ingolf" station, Stat. 38, 1870 fath., temp. 

 1.3, 9 species of Tanaidacea and 8 species of Isopoda were secured, but not a single specimen of Cumacea. 

 At Stat. 78 (799 fath., temp. 4.5) an enormous bottom material, especially sponges, was hauled up, and 

 it contained 9 species of Tanaidacea and 22 species of Isopoda, but only 2 species of Cumacea. Stat. 24 (1199 

 fath., temp. 2.4) yielded of Tanaidacea 12, of Isopoda 15, but of Cumacea only 6 species. The extremely 

 rich Stat. 36 (1435 fath., temp. 1.5); at which only a rather small quantity of bottom material was hauled 

 up, yielded n species of Tanaidacea, 18 species of Isopoda living at the bottom (besides 2 bathypelagic 

 species) and 9 species of Cumacea, thus a proportionately good number of the last-named order. From Stat. 

 25, 582 fath., temp. 3.3, thus more moderate depth, I had 8 species of Tanaidacea, 16 species of Isopoda, 

 and 1 1 species of Cumacea. But while all the stations now mentioned were the only places really rich as to 

 Tanaidacea and Isopoda, only two among them, viz. Stat. 36 and Stat 25, contained a good representation 

 of Cumacea, and from the last-named station with its 582 fathoms the harvest was richer than from Stat. 



