Alaskan Records of Eurytemora — Wilson 
511 
Kiefer’s brief description of two males from 
Paramushir Island in the Kuriles of northern 
Japan agrees in most points with Eurytemora 
composita. It is like the Alaskan form in having 
hairs on the anal segment. There are some 
slight differences in the fifth leg, though the 
proportions are similar. Without knowing the 
characters of the female, it would not be en- 
tirely correct to ascribe Kiefer’s specimens to 
composita. However, the widely separated Tur- 
kestan and Alaskan localities suggest the 
Fig. 7. Eurytemora composita Keiser. a, Male, leg 5, 
posterior view; b, male, leg 5, detail of apex of left 
exopod, posterior view; f, male, urosomal segments 
4-5 and caudal ramus; d, female, leg 5. 
probable occurrence of the species in inter- 
mediate places. 
The occurrence of Eurytemora composita in 
an isolated lake of western Asia led Gurney 
(1931: 186) to suggest its origin from one of 
the species of the Caspian Sea (£. affinis, velox, 
grimmi). Such a supposition is now difficult 
to maintain. The wider distribution of the 
species, as evidenced by its presence on the 
Bering coast of Alaska and its possible oc- 
currence on the northeast coast of Asia, sug- 
gests instead a northern origin. This is sup- 
ported by the fact that composita is closely 
allied to E. raboti Richard, which occurs in 
fresh and brackish ponds in the Arctic regions 
(Spitzbergen, Novaya Zemlya, the White Sea 
coast). The relationship of these two species 
has been pointed out by Smirnov (1929: 320) 
and Gurney (1931: 186). The presence of E. 
composita in an isolated brackish lake in eastern 
Turkestan may be fortuitous or may indicate 
the western edge of its distributional range. 
SUMMARY 
A new fresh-water species, Eurytemora yu- 
konensis, is described from several localities 
on the lower Yukon River, Alaska. 
Eurytemora composita Keiser is recorded and 
described from ponds at Unalakleet, Norton 
Sound, and St. Lawrence Island, Bering Sea, 
Alaska. It has been known only from eastern 
Turkestan. Two unidentified males described 
by Kiefer from the Kuriles, Japan, are similar 
to the Alaskan material and may be the same 
species. Since E. composita is alliod to the Arc- 
tic species, E. raboti, its occurrence in Alaska 
suggests a northern rather than a Caspian 
origin. 
REFERENCES 
Gurney, Robert. 1931. British fresh- water 
Copepoda. Vol. I. 238 pp., 344 figs. Ray 
Society, London. 
Keiser, N. 1929. Uber eine neue Art der 
Gattung Eurytemora— Eurytemora composita 
sp. nova. Zool. Anz. 80: 301-305, 6 figs. 
