Cyclops kolensis in North America — Reed 
DISCUSSION AND CONCLUSIONS 
The presence of Cyclops kolensis Lilljeborg 
on the North American continent is established 
by the examination of new material. It seems 
unwise in our present state of knowledge to 
designate subspecies by formal trinomials. It is 
possible, by measuring enough morphological 
characteristics and selecting among them, to find 
at least one feature in which the animals of each 
lake differ from all others. Extended to the ab- 
surd conclusion each lake contains its own sub- 
species. 
The effect of environment on the morphology 
of C. kolensis is not clear from the evidence. 
Environmental factors, such as temperature, 
turbulence, and food, are believed to affect the 
morphology of some species of cyclopoid 
copepods. How true this may be for C. kolensis 
cannot now be told. Animals living in ponds in 
Sweden exhibit several features in common with 
those dwelling in Lake Baikal; others living in 
nearby ponds on St. Matthew Island show 
features in common and also differences. 
Species of supposed immediate common an- 
cestry could be expected to share many features 
in common. Thus, if minor differences could be 
consistently associated with forms exhibiting 
reproductive isolation they would be sibling 
species — not subspecies. We cannot say whether 
or not different populations of C. kolensis are 
reproductively isolated. Geographic separation 
and the fact that local differences are discernible 
would suggest that gene flow at least is re- 
stricted. The possibility of sibling species is not 
ruled out by present evidence. What does appear 
to be ruled out is the desirability of using sub- 
specific names. 
ZUSAMMENFASSUNG 
Cyclops kolensis Lilljeborg wurde wahrend 
neuer Untersuchungen auf der Insel St. Matthew 
und bei Point Barrow, Alaska gefunden. fiber- 
priifung der Marsh Sammlungen (U. S. Na- 
tional Museum) brachte zusatzliche Species vom 
arktischen Kanada an’s Licht. 
Acht anatomische Eigenschaften wurden in 
drei Populationen von Tieren Alaska’s gemessen, 
die sich als nfitzlich erwiesen, Species von 
Cyclops zu unterscheiden. Masse und Verhalt- 
265 
nisse zwischen Massen von C. kolensis von 
Alaska und von Schweden, Deutschland, Polen, 
Baikal See und andern sibirischen Seen wurden 
statistisch verglichen. Masse von Tieren aus- 
serhalb Alaska’s waren der Literatur entnommen 
worden. 
Die statistischen Vergleiche fuhrten zu keinem 
klaren Ergebnis. Die meisten Populationen un- 
terschieden sich mit Signifikanz zumindest in 
einer Eigenschaft von alien andern; jedoch 
unterschied sich nicht eine Population in alien 
Eigenschaften von alien andern. 
Ehe nicht mehr fiber die Morphologic, Ver- 
teilung und Okologie von Cyclops kolensis 
bekannt ist, erscheint es unweise, Subspecies- 
Namen zu verleihen. 
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