REPORT ON THE AMPHIPODA. 141 



The Grevettines he subdivides into the tribe of the Savtevrs and the tribe of the Marcheurs. 

 In the former he includes the following genera, the first two as arenicoles, the remainder as 

 aquatiques : — 



1. Orchestia, Leach, to which he transfers Talitrus longicornis, Say. He here describes 



Orchcstia Fischerii, Milne-Edwards, with a reference to " Mem. de la See. d'Hist. nat. de 

 Paris, t. 5. pi. 25, fig. 14." This species Spence Eate refers to Orchedoidea. 



2. Talitrus, Latr., including Talitrus Beaucoudraii, n. s., which Spence Bate thinks is probably 



the female of Orchestia littorea, with Klein's Saltator and Audouin's 0. Cloquetii. 



3. Lysianassa, n. g., thus described : — " Les Crevettines, que nous pla^ons dans cette nouvelle 



division g^n^rique, se rapprochent des Talitres par la structure de leurs pattes, dont aucune 

 n'est prehensile ; ceUes de la premiere paire sont assez fortes, presque cylindriques dans 

 toute leur longueur et termin6es par un article court et presque immobile. La forme des divers 

 appendices de la bouche est au contraire la meme que dans les Crevettes et les autres genres 

 de la subdivision des Aquatiques ; les antennes sont quelquefois tres-courtes, mais les 

 superieures sont toujoiu's au moins aussi longues que le pedoncule des inferieures et se 

 terminent par deux tigelles annel^es." He describes and figures "Lysianassa Oostm," n. s., 

 pi. 10, fig. 17, and gives brief notes upon " L. Chauseica," n. s., which he afterwards 

 transferred to a new genus Alihrotus. 



4. Gammarus, Fabr. in which he describes and figures Gammarus ornatus, n. s., pi. 10, figs. 1-8, 



in his account of this species calling attention to what he then thought a unique phenomenon, 

 the calceoli, as they were afterwards called, on the flagella of the lower antennae, " une 

 petite cupule membraneuse, transparente, invisible h, I'ceil nu, legerement ciliee sur les bords, 

 fix^e k I'antenne par sa base et entouree de quelques polls (pi. 10. fig. 2, b) ; " he describes 

 " Gammarus Olivii," n. s., pi. 10, figs. 9, 10, which by both Sp. Bate and Boeck is referred 

 to Gammarus marinus, Leach; he describes and figures "Gammarus Othonis," ]A. 10, figs. 

 11-13 which by Bate is referred to Mecjamcera, by Boeck to Mxra, longimanus, Leach; he 

 gives brief distinguishing marks for Gamm.arus atlanticus, n. s., which he afterwards described 

 as Lysianassa atlantica; "Gainmarus Impostii" n. s. = Mcera grossimanus, Montagu 

 (according to Spence Bate in the British Museum Catalogue of Amphipodous Crustacea) ; 

 "Gammarus Dugesii," n. s. = Melifa palmata, Montagu ; Gammarus podager, n. s. = Melita 

 podager (B. M. C.) ; " Gammarus Savii," n. s. = Mcera Savii (B. M. C), but a doubtful 

 species ; Gammarus hrevicaudus, n. s., afterwards corrected into Gammarus brevicaudatus = 

 Gammarella hrevicaudata (B. M. C). As " Espfeces douteuses " he gives 1. Oniscus 

 arenarius, 0. Fabr., referring to it Gammarus Homari, Fabr., and Strom's Marflue ; 

 2. Oniscus alyssinus, 0. Fabr. ; 3. Gammarus marinus, Eisso, and Gammarus palmatus 1 

 Montagu. 



5. AmpMtlioe, Leach, in which he describes and figures AmpMtlioe costata, n. s., pi. 10, 



figs. 14-16, a species transferred by Spence Bate to the genus Pherusa of Leach, with a 

 note of Milne-Edwards' error in attributing four joints to the mandibular-palp in the 

 text, though he correctly figures only three ; he gives very concisely distinguishing marks 

 for "AmpMtlioe Marionis." n. s.=Dexam.ine spinosa, Montagu (B. M. C.) ; "AmpMtlioe 

 Jurinei," n. s. = Pherusa fucicola. Leach (B. M. C); " Amphitlwe Pausilipx," n. s., which 

 he afterwards called Amphitlwe Pausilipii" ; " Amphithoe Inda," n. s., afterwards called 

 "AmpMtlioe Indica," and said to be very near the preceding species; "Amphithoe 

 Reynaudii," n. s.; Ampihithoe armorica, n. .s., which "appears to belong to the genus Nicea," 

 according to the B. M. C, p. 243, note ; " Amphithoe Swammcrdamei," n. s., afterwards 

 called Amphitoe Stvammerdamii = Atylus Stuammerdamii {B. M. C.) ; Amphithoe pelagica, 

 n. s. ; "Amphithoe Prevostii," n. s., on which see below. 



6. Isssa, n. g., thus described : — " Dans le genre Isaea, la forme gendrale du corps est la meme que 



chez les Crevettes ; les antennes superieures se terminent aussi par deux appendices annel6s ; 



