Proceedings of 

 the United States 

 National Museum n 3$*gTc£> 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Volume 124 1967 Number 3627 



Echiniphimedia, 

 An Amphipod Genus 

 From the Antarctic Ocean 



By J. Laurens Barnard 

 Associate Curator, Division of Crustacea 



Echiniphimedia, a member of the Acanthonotozomatidae, is rep- 

 resented by three known species confined primarily to the sub- 

 littoral and upper bathyal depths of antarctic seas. They are the most 

 extraordinarily ornamented members of the family in their departure 

 from the ordinary plan of paired dorsal teeth or low numbers of 

 teeth. Two members of Echiniphimedia are virtually covered with 

 medium to long spikelike fixed teeth and are rivalled in the density of 

 their ornamentation only by a member of the Paramphithoidae, 

 Uschakoviella Gurjanova, which has dense articulated spines covering 

 the body. The degree of dorsal segmental ornamentation among 

 benthic Amphipoda seems to increase directly with latitude, the 

 tropics having few such species and the polar regions having large 

 numbers of "spiny" amphipods. Ornamentation appears to be highly 

 variable among polar species, differing in extent from youth to 

 senility, from deme to deme, or within demes. The extent of intra- 

 specific variations has scarcely been measured nor has it been identified 

 with ecotypic and racial existence. 



The purpose of this paper is to review the known species of the 

 genus, report on variations among their individuals, elucidate a 



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