Proceedings of 
the United States 
National Museum 
SMITHSONIAN INSTITUTION +- WASHINGTON, D.C. 
Volume 120 1967 Number 3567 
TAXONOMY, DISTRIBUTION, AND POLYMORPHISM 
IN THE LABIDOCERA JOLLAE GROUP 
WITH REMARKS ON EVOLUTION WITHIN THE GROUP 
(COPEPODA: CALANOIDA) 
By ABRAHAM FLEMINGER ' 
Introduction 
Acceptance of the idea that the prevailing mode of speciation in 
sexually reproducing animals begins with genetic divergence of 
spatially separated stocks is widespread and rightly so. With regard 
to the pelagic biotope of the oceans, however, this concept is based 
more on faith than on documentation, although several noteworthy 
efforts have been published (e.g., Bowman, 1955; Brinton, 1962; 
Ebeling, 1962; Davies, 1963). 
Study of evolution in pelagic metazoans is impeded by a combination 
of factors, including (1) confluence of oceans and the relative obscurity 
of isolating barriers; (2) uncharted variability of major current systems 
with climatic changes over time; (3) general lack of detailed knowledge 
regarding the biology and range of pelagic organisms; (4) scarcity of 
information on the kinds and extent of morphological variation within 
and between populations; (5) extensive economic and logistic re- 
quirements for collecting oceanic species; (6) continuing prevalence of 
_ 1Scripps Institution of Oceanography, University of California, San Diego, 
Calif. 
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