554 PROCEEDINGS OF THE NATIONAL MUSEUM vol. us i 



G 21643 to the Smithsonian Institution) is acknowledged. We are i| 

 indebted to Mr. Hilliard for collections, some physical data and critical i 

 reading of the manuscript, and to Miss Gayle Heron for making , 

 available, prior to publication, a copy of her paper (Heron, 1964). 



Inland Lakes, Pools, and Ponds 



Only one species of Eurytemora, new to science, occurred in samples 

 from 4 of 10 small, shallow, permanent, unnamed bodies of fresh 

 water (herein termed lakes) and 7 nearby smaller, less permanent 

 pools and ponds situated in wet Carex marsh and meadow. One 

 lake (reference no. 9), located about 11 miles inland from Cape 

 Thompson, has an outlet to a small creek draining to the Kukpuk 

 River. The other three lakes, located near one another about 7 

 miles inland, have no defined inlets or outlets, the incoming water 

 originating from drainage of the surrounding marsh during snowmelt 

 and rains. Emergent vegetation occurs at the edges of the lakes; in 

 the type locality (Lake 4), broad-fingered beds of Arctophila extend 

 toward the center. The lakes are ice-free for about 2^-3 months of 

 the year (from early to mid-June to early September). In 1960, the 

 maximum temperature range recorded weekly for Lake 4 from July 1 

 to August 11 was 13.2-15.5° C; by September 4, this dropped to 4° C. 



Quantitative and qualitative samples were taken at regular intervals 

 and stations from the open, deep water of Lake 4 with no. 12-mesh 

 plankton nets on an open Clarke-Bumpus sampler. The other lakes 

 were sampled on one or two dates by casting nets from the shore. 



The existence of the new species, described below, has been known 

 for many years from immature copepodid stages collected at Umiat 

 (Wilson collection) but it was impossible to define until adults were 

 collected in the Cape Thompson samples. The Umiat collection and 

 one made by Tash in the Noatak region extend the known distribu- 

 tion of the species beyond the Cape Thompson region. 



Family Temoridae 



Eurytemora arctica, new species 



Figures 1-3 



Type locality. — Unnamed lake (reference no. "Lake 4"), about 

 7 mUes inland from coast of Chukchi Sea, Cape Thompson region, 

 Alaska, 68°11'09" N., 165°42'05" W.; surface area, 2.1 hectares; 

 maximum depth, 2.4 meters. 



Types.— Holotype 9, USNM 106647; allotype c^, USNM 106648. 



Definition. — Female: Metasomal wings and genital segment not 

 laterally expanded ; caudal rami slightly longer than urosome segments 

 2 -}- 3; antennules reaching to near end of metasome. Leg 5: Exopod 



