12 j Canadian Arctic Expedition, 1913-18 



It has been found only in Scandinavia, in bodies of water in the north of 

 Sweden, and in lakes north of Kristiania, in Norway. Lilljeborg states that it 

 is mostly found in small bodies of water, and is rare. In the collections of the 

 Canadian Arctic Expedition it occurred in only one locality, a lake at Konganevik 

 (Camden bay), Arctic Alaska, in a gathering made June 26, 1914. Only a few 

 individuals were found. 



The correspondence with the descriptions of Sars and Lilljeborg was very 

 close. The antennae, shown in PL IV, fig. 9, are composed of twelve segment-. 

 and about equal in length the first cephalothoracic segment. In the abdomen, 

 shown in PL IV, fig. 4, the second, third, and fourth segments nearly equal each 

 other in length, and together are somewhat shorter than the first segment. The 

 branches of the furca, PL IV, fig. 10, are five times as long as broad and the lateral 

 seta is placed just distad of the middle. The last abdominal segment is armed 

 on its posterior border with fine spines. The formula for the spines of the 

 terminal segments of the exopodites of the swimming feet is 3, 4, 4, 4, The 

 fifth foot, PL IV, fig. 8, resembles that of the viridis group, but the second segment 

 is shorter and cylindrical; its length and width are about the same. The form 

 of the receptaculum seminis is shown in PL IV, fig. 11. 



The length of the females measured varied from 1.55 mm. to 2.55 mm. 

 In the original description in 1863 Sars states the length as about 2 mm., and 

 Lilljeborg, in 1901, says the length of the females is from 1 .8 to 2. 1 mm. 



This species is readily distinguished by its short 12-segmented antennae, 

 its elongated furca with the lateral seta about midway of its length, the fifth 

 foot, and the receptaculum seminis. 



The finding of this species is of a good deal of interest, for it has hitherto 

 been known only from Scandinavia, and there was a rare form. It may be 

 expected that future collections will show that it occurs in the lands inter- 

 vening between the Scandinavian peninsula and the Arctic shore of North 

 America. 



DISCUSSION OF THE COPEPOD COLLECTIONS WITH REFERENCE TO DISTRI- 

 BUTION. 



Of the species of these collections, C. americanus is very widely distributed, 

 and its occurrence in the Arctic has no significance. C. magnus is probably a 

 cold-water form. 



The genus Eurytemora is widely distributed in brackish water. It is 

 interesting that it was found in a new species. 



The only account published previously of the presence of the genus Hetero- 

 cope in America, was by Juday and Muttkowski in their description of H. 

 septentrionalis, and it would appear that it may be rather widely distributed 

 across the American continent. In Europe, and Asia the genus is found most 

 commonly towards the north and in larger bodies of water, but it extends to 

 central Europe. 



Limnocalanus macrurus is the only species of this genus which has hitherto 

 been found on the American continent. Brehm, 1911, also reports L. macrurus 

 in Greenland. It will be interesting from future collections to find out how 

 widely L. johanseni is distributed. 



Diaptomus bacillifer is new to America, and, as already stated, while dis- 

 tinctly a cold-water form, is probably the most widely distributed species of 

 the genus. 



Diaptomus arcticus is a new form very closely related to D. shoshone and 

 D. wardi, and it will be interesting to know the geographical limits of the three 

 species. 



The occurrence of Cyclops strenuus on the borders of the Arctic ocean, with 

 the former records of its presence in lakes in New York, makes it probable that 

 it may be found anywhere in North America north of the latitude of New York. 



