REPORT ON THE AMPHIPODA. 327 



1S60. VOLLENHOVEN, SaMUEL CONSTANT SNELLEN, VAN. 



Naturlijke Historic van Nederland. De dieren van Nederland. Overzigt der 



gelede dieren. Haarlem, 1860. 



Under " de Amphipoden of vlookreeften," he mentions Roeeers species imder the name " Gam- 

 marus Roeselli Gerv.," PL ii. fig. 1, distinguishing it from " Gammarus Puleic L.," and 

 Gammarus puteamis Koch. He mentions also Talitrus saltator, Edw., PI. i. fig. 5 ; 

 Orchestia littorea, Leach, PI. i. fig. 6, of which he discusses the phosphorescence ; " CoropMum 

 longicorne Desm.," PI. i. fig. 7 ; " CapreUa lohata Latr.," of the female of which he gives a 

 woodcut; and lastly, '■'■ Leptomera pedata Latr.," PI. ii. fig. 2, with a reference to Slabber, 

 " Natuui-k. Verlust. Plaat X, fig. 1, 2." The figure shows that Proto veniricosa, 0. F. M.^ is 

 in question, though the explanation of the plate calls it Ccqn'ella linearis, probably by an 

 accidental slip. 



1861. Bate, C. Spence. 



On the Morphology of some Amphipoda of the division Hyperina. The Annals 

 and Magazine of Natural History. 3 Ser. Vol. VIII. 1861. pp. 1-16. Pis. I.-II. 



A new species, "Vihilia Edwardsii" is described, and tho differences between the mother and the 

 young taken from the incubatory pouch are given in detail. A new genus, Platyscelus, is 

 thus defined : — " This genus agrees in every respect with Dana's genus Dithyrus, except 

 that, after the basa in tlie third and fourth pairs of pereiopoda, the remaining joints are 

 developed, whereas in Dithijrus they are wanting." In the Brit. Mus. CataL, p. 329, Spence 

 Bate adds a note to his description of this genus, " it appears to me to be not improbable 

 that Platyscelus may prove to be the female of Typhis, from which it differs only in the 

 form of the superior and length of the inferior antennae." With Tijp)his ovoides, Risso, 

 Claus decisively identifies the species Platyscelus serratus here described as new. Typhis 

 being preoccupied, Claus renames the genus Eutijphis, though on his own showing, Dithyrus, 

 Dana, Thyropus, Dana, and Platyscrlue, Spence Bate, have each, in the order named, a 

 prior claim. 



The new genus Brachyscelm is thus defined : — " Cephalon anteriorly rounded. Eyes occupying 

 the lateral walls, which encroach upon the inferior margin. Pereion not distended, nearly 

 as deep as the eephalon, and not wider. Pleon nearly as broad as the pereion ; fourth and 

 fifth segments fused together. Antennse obsolete or very rudimentary. Oral appendages 

 membranous and rudimentary. Gnathopoda completely subchelate. Pereiopoda having the 

 basa of tho three posterior pairs largely developed ; fifth pair having the remaining joints 

 not obsolete. Pleopoda biramous. Telson single." The type species is Brachyscelus crus- 

 culum, of which the female and young are described and figured. 



!Mr. Spence Bate remarks in regard to the young of the genera he has been discussing, that the 

 adult form which approximates nearest to them is that of the genus Oxycephalus, " which 

 bears so close a resemblance to the young of Platyscelus, that they might readily be accepted 

 as belonging to one genus." Again, he says, M. Gm^rin-Mcneville's " figure of the young 

 of Rhahdosoma appeared to me to be a fair representation of an adult Oxycephalus." He 

 thinks that the unimpoverished type in many genera of the Hyperina is to be found nearer 

 to the young than to the adult form. Alluding to the dwelling of many Hyperina in the 

 gill-cavities of Medusw, he thinks we may assume that eyes, small in the type, have been 

 monstrously increased in these creatures to make up for the depreciation of light tliat reaches 

 them through the transparent animals they lodge in. To find out their nearest allies among 

 the normal Amphipods, we must compare their young with tho more aberrant forms, and 



