424 THE V^OYAGE OF H.M.S. CHALLENGER. 



fragilis, Goes ; the (Edicerinse, species CEdiceros hoi-ealis, Eoeck, retransferred from 

 Monoeulodes to CEdiceros ; CEdiceros hjnceus, Sars ; the Pleustinae, a new family, species 

 Pleustes panoplus, Xr.; Parapleristes gracilis, n. g. et s., perhaps the same as Paramphithoe 

 exigua, Goi?s, and Paraivphitlwe glabra, Boeck : the Iphimedince, species Vertumnus serratus, 

 Fabricius (of which the name Vertumnus, White, being preoccupied, has since been changed 

 by Boeck to Acanthonotozoma) ; the Gammariufe, species Gammarus locusta, L. (not figured), 

 AmathiUn sahini, Leach, Amathilla ping^ds, Kr.; the Atylinae, species Aiylus carinatus, 

 Fabricius, Atylus smittii, Goes (not figured), Acanthozone hijstrix, Owen, probably, as 

 Miers has pointed out, a new species, distinct from Owen's ; Paramphithoe inemiis, Kr. ; 

 Paramphithoe fulvocincta, Sars; Parampildthoe megalops, n. s.; the Ampeliscinse, species 

 Ampelisca eschrichtii, Kr., with the suggestion that Ampelisca viacrocephala, Lilljeborg, may 

 be only a local variety ; the Podocerinse, species Podocerus anguipes, Kr.; the Corophinse, 

 species Glauconome leucopis, Kr. (not figured) ; the Hyperidfe, species Themisto lihellula, 

 Mandt ; the Caprellida;, species JEgina spinifera. Bell, with which he identifies Aiginella 

 echinata, Boeck (the name JEginella being probably an accidental sUp of the pen for 

 ^gina). 



The Syrrhoinee are said to come near the CEdicerinK in general form and in the structure of the 

 mouth-organs, although having this distinction that only the left mandible is provided with 

 a 2^>'("'essus accessorius. (But this distinction is not universal in the group.) 



In the Pardaliscinse, Dr. Buchholz corrects the supposition of Boeck that a processus accessorius 

 is wanting to the right mandible. He also considers that Bruzelius and Boeck have both 

 of them confused the joints in the gnathopods of Pardalisca cuspidata, that which they 

 have taken for the wrist being really the hand, and the finger being, contrary to the general 

 rule in Amphipods, two-jointed. This would be extremely remarkable, and would contra- 

 vene the rule well laid down by Spence Bate that in the Amphipoda the third (free) joint 

 always underrides the fourth in the gnathopods and overrides it in the peraeopods, but my 

 own observation of members of the genus Pardalisca compels me to believe that the earlier 

 authors are right, and Dr. Buchholz himself in error. It is in any case clear from the 

 figures that Dr. Buchholz and Boeck are not referring to the same species under the title 

 of Pardalisca cuspidata, Kr. The species so named by Buchholz agrees with Pardalisca 

 abijssi, Boeck, a specimen of which was brought home by the Challenger and is figured in 

 this Report.. 



From the Leucothoinfe, which he considers too heterogeneous a groujj, Dr. Buchholz is inclined 

 to transfer the genus Tritropis (since called Rhachotropis by S. I. Smith) to the group 

 containing Paramphithoe. 



For the Pleustiuas, a new family, he mentions as characteristics, the antennje rather short, the 

 lower shorter than the upper (sexual differences not ascertained); the head small, with dis- 

 tinct, well-developed rostrum, the eyes small and lateral ; the body frequently carinate, the 

 first four side-plates well developed ; the mandibles with broad dentate process but no molar 

 tubercle ; the gnathopods large, subchelate, the three last pairs of pera3opods not much 

 elongated, and the seventh not especially so ; the uropods slender, pretty strongly elongated. 



It is a little difficult to reconcile the expression " das giinzliche Fehlen des Kauhockers der 

 Mandibeln " in the above account of the family, with the description " des sehr verkiim- 

 merten Kauhockers " of Pleustes p)anoplus. This degenerate molar tubercle is figured by 

 Buchholz himself, as well as by Kr0yer and Boeck. 



The new genus Parapleustes is thus defined : — ■" Corpus epimeris quatuor anterioribus mediocribus, 

 dorso rotundato epidermide tenui. Rostrum exiguum. Antenna3 breves, inferiores [quam] 

 superiores breviores. ^landibulte processu dentali brevi, lato cum jDrocessu accessorio coalito, 

 tuberculo molari nullo. Labium superius breve et latum, profunde emarginatum. Ceterum 

 generi Pleustes valde affinis." 



