of Grinnell Land and North Greenland. 493 



numerous and irregularly crowded. Dr. Moss sent me with 

 his specimen the following note : — 



" When the snoAv melted into pools on the ice-foot a mile to 

 the north-west of the ' Alert 's ' winter quarters, a quantity of 

 '■ jetsam ' thrown up by the sea was found lying on the 

 surface of the ice. It consisted of Laminariee in every stage 

 of decay, small fragments of coniferous drift-wood very rotten 

 and old, many specimens of Arcturus^ and a few of Nymphon ; 

 and he)-e and there the accompanying shells lay sunken into 

 little thimble-shaped pits in the ice. They were extremely 

 fragile, and almost all imperfect. They could not be handled 

 with cold fingers ; but with the help of a bit of laminarian 

 frond a few perfect shells were raised and bottled. Tlie shell 

 enclosed in the tube is the only specimen of its sort I could 

 get in a perfect state. I saw several others ; but they crumbled 

 at the slightest touch." 



I exceedingly regret that my friend Capt. Feilden is under 

 the impression that in my former paper I criticised too severely 

 the conchological results of the Expedition. This criticism I 

 never intended. It is quite true that I expressed disappointment 

 with the conchological results of the expedition ; but I must 

 repeat what I said on that occasion : — " I have no doubt that 

 the Naturalists did their best." The memorandum of Dr. 

 Moss, which I have above quoted, shows that the specimens 

 were collected under difficult circumstances. Capt. Feilden 

 evidently spared no trouble, nor flinched from his task with 

 the thermometer many degrees below zero. Judging, how- 

 ever, from the species already recorded, and from their asso- 

 ciation with other species elsewhere in arctic seas, I cannot 

 help believing that the list of polar Mollusca is far from being 

 exhausted. Shallow water only has hitherto been dredged 

 north of latitude 70° 30'. The paucity of species in the 

 polar seas, if it exists, may be due to the absence of those 

 marine currents which promote and regulate the distribu- 

 tion of species in other seas. Temperature does not ap- 

 pear to restrict the distribution, because individuals are 

 abundant in the highest latitudes, and in the ' Porcupine' 

 expedition of 1869 there was no diminution of species or 

 individuals in the " cold area :" although the normal tem- 

 perature in the greater part of this area was between 29° 

 and 32° F., more species of Mollusca occurred there than 

 in the adjacent " warm area." The naturalists of the Nor- 

 wegian expedition found a varied fauna in the coldest parts 

 of the ocean which they have lately explored, between Iceland 

 and Jan Mayen's Isle. The collection of Post-tertiary fossils 

 made in latitudes within ten to seven degrees of the pole is espe- 



