The Families and Genera of Marine Gammaridean 



Amphipoda 



Introduction 



Keys and diagnoses, with illustrations, to the families and genera 

 of marine gammaridean Amphipoda are presented here in the form 

 of a handbook. Since 1906, when Stebbing monographed this suborder, 

 the number of famihes has been increased by 25 percent, the number 

 of genera by 200 percent and the number of species by nearly 200 

 percent (J. L. Barnard, 1959d). Stebbing's general arrangement of 

 families and genera remains substantially intact, but the discovery of 

 many additional species has required a considerable emendation of 

 familial and generic hmits. The near absence of phyletic monographs 

 and the plethora of faunal compilations widely scattered in the litera- 

 ture have hindered advances in classification of the group. Ready 

 identification of taxa not only by nonspeciahsts but even by experts 

 has become extremely difficult because of the lack of a modern focal 

 point. 



The present work is at best a stopgap. Speciahsts recognize that 

 much exploration and discovery remain to be accomplished in the 

 Amphipoda (witness the numerous new haustoriid taxa discovered by 

 Bousfield, 1965). No speciahst is nearly satisfied with current classifi- 

 cation at familial levels. Many genera are extremely confused, not 

 only for the lack of clear description of their type-species but for the 

 obviously erroneous inclusion of many of their congeners. Few studies 

 on population variabihty have been pubHshed and the criteria to be 

 applied at generic and famihal .evels have rarely been tested even by 

 dialectical means. 



No radical changes in classification are proposed herein, but numerous 

 problems are noted. The purpose of this paper is to assemble the 

 famihes and genera within the previously arranged general scheme 

 and to provide rapidly usable (and thus simplified) means for their 

 identification. In this way the keys coincide with the pubhshed 

 literature and may be of greater help than would be a brief, completely 

 revised system, which might not stand the test of time. Hopefully 

 this paper will encourage recruitment of new taxonomists and reUeve 

 some of the burdens of identification now overwhelming the few active 



