NO. 1589. FRESH-WATER CRUSTACEA— CUSHMAK 711 



This species was originally described from Bering Island, one of 

 the Commander Islands off Alaska. It has also been found in Green- 

 land, Nova Zembla, and along the Arctic coast of northern Europe. 

 It is clearly an Arctic species and its occurrence in southern Labrador 

 is only an added indication of the boreal conditions there, although 

 so much farther south than most of the previous records. 



Genus CHYDORUS Leach; Baird 1843. 



CHYDORUS SPHiERICUS (O. F. MuUer). 



Plate LXII, fig. 4. 



Lynccus sphwricus O. F. Muller, Entomostraca seu Insecta testacea, qua? 



iu aquis Danise et NorvegiiP reperit. descripsit, et iconibus iUustravit, 



1785, p. 71, pi. IX, figs. 7-9. 

 Cliydorus sphcericxis Baird, British Entomostraca, 1850, p. 12G, pi. xvi, fig. 



8. — LiLLJEBORG, Cladocera Suecife, Nova Acta Reg. See. Sc. Upsala, 3d 



ser., XIX, 1900, p. 561, pi. lxxvii, figs. 8-25. 



Length of females about O.-IO mm. 



This small species is to be looked for in every collection of Cla- 

 docera, as it has a worldwide distribution, being found in North and 

 South America, Europe, Africa, Asia, and Australia. It is found 

 far inside the Arctic Circle in Spitzbergen and Nova Zembla, and in 

 warmer regions such as Algiers and Senegal. A number of speci- 

 mens were obtained at Funk Island, Newfoundland, by Mr. Bryant 

 in May, 1906. It was not obtained at Labrador, probably because 

 no bottom material was taken, the forms being all surviving species 

 and taken with a net. The post-abdomen is shown in Plate LXII, 

 fig. 4. 



Order COPEPODA. 



Family CALANID^. 



Genus DIAPTOMUS ^Vest^A^ood, 1836. 



DIAPTOMUS EISENI Lilljeborg. 



Plate LXII, figs. 5, G. 



Diaptomus ciseni Lilljeborg, in De Guerne, J., and Richards, J. ; Revision 

 des Calanides d'eau douce, Mem. Soc. Zool. Fr., II, 1889, p. 96, pi. i, figs. 

 19, 20, 33. 



Length of males about 3.5 mm. 

 . The fifth feet of the male of this sj^ecies are shown in Plate LXII, 

 fig. 6, and the tip of one of the stylets in fig. 5. This is a compara- 

 tively large species and was found in considerable numbers by Doctor 

 Allen at Battle Harbor, Labrador, July 14, 1906. The species is 

 common to Europe and America, and is widely distributed in this 

 country. For help in the identification of this species I am indebted 

 to Mr. A. S. Pearse, to whom specimens were submitted. 



