128 THE VOYAGE OF H.M.S. CHALLENGER. 



gnatliopods that tliey are probably tbe first pair, not tbe second as has been hitherto 

 supposed. The large fourth joint must be the -wrist not the hand. The finger is not 

 shown. Judging only by the general appearance, in the absence of other evidence, one may 

 reasonably assign the species rather to Talitrus than to Orcliestia. In fig. 1, which repre- 



Fig. 21. 



sents the mandible of Orchestia Montagui, here reproduced, it will be seen that Savigny 

 represents the rudiment of a triarticulate palp. In his figure of the maxDlipeds of the same 

 species he represents the outer plate as articulated with the joint of which it is the expansion. 

 This must be an error. 



1826. ElSSO, A. 



Histoire Naturelle des principales productions de I'Europe Meridionale et parti- 

 culierement de celles des euvirons de Nice et des Alpes Maritimes. Tome 

 cinquieme. Paris, 1826. 



In the preliminary notice Eisso observes that " tous les genres d'amphipodes aiment k se laisser 

 balancer mollement par les vagues sur la surface des eaux," a statement which must be 

 received with some reservation, in regard to the Orchestidse and others. The crustaces 

 amphijjodes here form the third Order. Genera and species, which had been already 

 described in Risso's earlier works, are nevertheless here marked as new, sometimes without 

 a reference to the earlier description. Tbe genus Phrodna has the following fresh defini- 

 tion ; — " Corps assez solide, oblong ; tetemoyenne; dix pattes, toutes monodactyles ; dernier 

 article de la queue arrondi, sans appendices." The expression "sans appendices" is 

 intended to distinguish Phrodna from Phronima, in which Eisso fancied that the telson 

 had appendages. The genus Tij^Ms is re-described; — "Corps solide, ovoide ; tete large; 

 dix pattes, la premifere paire didactyle ; dernier article de la queue conique, aigu, sans 

 appendices." Anew species, named Gammarus marinus, is thus described "corpore sub- 

 ovato, intense griseo ; punctulis saturate griseis ornato ; antennis pedibusque pallidioribus." 

 The name being preoccupied by Leach, and the descrii3tion very inadequate, this species 

 has been allowed to drop by subsequent authors. Under the heading "les antennes 

 superieures presque aussi longues que les inferieures," the new genus Enoiie is described : — 



