REPORT ON THE AMPHIPODA. 475 



1878. Catta, J. D. 



Sur un Amphipode nouveau, le Gammarus Rhipidiopliorus. Actes de la 

 Society Helv^tique des Sciences naturelles reunie h, Bex les 20, 21 et 22 aotit 1877. 

 60^ session. Compte-rendu 1876/1877. Lausanne, 1878. pp. 257-263. 



The Amphipod in question has been only found in a well at La Ciotat (Bouches-du-Rhone, 

 France), a hundred yards or so from the Mediterranean. The water of the well becomes 

 brackish in summer. Professor Catta observes that in the carpus and propodus of the 

 first periBopod his new species has, with exaggerated development, a character common also 

 to Gammarus 2iiilex and Gammarus locusta, in that these joints are " garnis d'immenses 

 polls plumeux disposes par rangees trans versales et entremel^s de piquants." From the 

 sweeping movement of these setae he formulates the name "Rhipidiopliorus {pnrihiov, 

 halai do plumes)." The first perteopod in this species, he says, is much longer than the 

 second ; the first uropods are much shorter than the second ; the third are enormons, 

 whether compared with those that precede or with the size of the animal, and have one 

 branch rudimentary ; the other branch " garnie de nombreuses rangees de grandes soies et 

 de piquants, est comi^osee de deux articles dont le dernier est assez reduit." 



An argument follows to show that the genus Niphargus ought to be again nerged in Gam- 

 marus. It is urged that in Gammarus pulex, and in Gammarus neylecfus, Sars, one ramus 

 of the third uropod is biarticulate, as in Niphargus; that Humbert's "Niphargus 

 puteanus, var. Forelii " has " des polls et des poinQons sur le bord post6rieur des dernlers 

 Somites," as in Gammarus; that the presence or absence of eyes is not of great im- 

 portance ; and that the telson is practically alike in the species assigned to both genera. 

 As to the dorsal hairs and prickles, he says, " G. Rhipidiopjhorus qui est Niphargus par 

 les antennes, le cinquieme Siagonopode et le Pl^on, porte aussi ces polls et ces piquants." 

 It may, on the other hand, be argued that in Niph.argus aquilex the biarticulate ramus of 

 the third uropods is strikingly distinguished from that in any species of Gammarus by the 

 length which the second articulation attains, as well as by its cylindrical shape. The 

 discovery of transition-forms between two genera will always cause some difficulty, but as 

 such forms have probably existed in innumerable cases where they have not been 

 discovered, it is a question how far the discovery of them should be allowed to interfere 

 with well-established distinctions either of genera or species. When Niphargus aquilex 

 and Gammarus pulex are side by side, it is rather the difiFerence of the fades than the 

 likeness which attracts attention. 



1878. Chatin, Joannes. 



Recherches pour servir h, I'histoire du batonnet optique chez les crustaces et les 

 vers. (Suite l). Annales des Sciences naturelles. Sixieme serie. Zoologie. Tome 

 VII. Paris, 1878. 



Accounts are given of the eye in Lysianassa sjnnicornis, Costa, fig. 24; Isxa nicea, Thor., fig. 

 25, 26 ; Caprrella acanthifera. Leach, figs. 28, 29 ; Epimeria, nov. sp., Catta, figs. 30-34. 

 This new species lives parasitic upon Suherites domuncula, Nardo. The pigment-sheath is 

 rouge vif, while other species of Epimnria have it brown, and others again almost black. 

 The genus, he thinks, requires a complete revision. 



