THE COPENHAGEN MUSEUM AND OTHER SOURCES. 417 



1888. Pereionolus Stebbiiig, ' Cliallenger' Amphipoda, pp. 81, 340, 318. 



1893. „ Delia Valle, F. u. Fl. G. Neapel. Moii. 20, Gammariui, p. 559. 



Body depressed, pleon strongly flexed. Head square, feebly rostrate, with the eyes on 

 the prominent front corners. Antennae short, the second shorter and much more 

 slender than the first, attached on the under surface of the head some way to the rear of 

 the first. Mouth-organs in general like those of Ipliiplateia, the maxillipeds excepted, 

 in which the palp does not reach beyond the outer plate, and is only three-jointed. 

 The limbs of the person also nearly as in Iphiplateia, except that the second joint of the 

 fiftli perseopods is very much smaller than that of the third and fourth pairs. All the 

 pleopods -with botli rami well developed, tlie peduncle laterally produced in the third 

 pair or in both the second and third pairs. The first uropods biramous ; the second much 

 shorter, uniramous ; the third one-jointed, obscure, completely covered by the telson, 

 which is entire. 



The type species, Fereioiiotus testtido (Montagu), seems to be almost certainly 



identical with Icridium fuscum Grube, while PliUas serratus Guerin is certainly distinct. 



I am indebted to M. Ed. Clievreux for a Mediterranean specimen labelled Icridium 



fuscum, but which has the first and second uropods both biramous as in the genus 



Phlias of Guerin. 



Pereionotus Tuomsoni, n. sp. (Plate 35 A.) 



The body is a broad oval. The medio-dorsal line throughout the peraeon and in the 

 first two segments of the pleon is raised to a carina, formed by a succession of processes 

 not quite so long as their respective segments, that on the first peraeon-segment being 

 preceded by an acute point directed forward. 



Head. The lateral angles extend a little in advance of the small, but distinct, 

 rostrum ; and, though on the whole rounded, they have a minutely acute point on tlie 

 inner side. 



The first four pairs of side-plates are without conspicuous setules on the distal margin. 



Eyes. Rounded oval, dark, situated on the lateral lobes of the head. 



First antennce. Tlie inner margin of the l)road first joint is indentured ; the second 

 joint cylindrical, not lobed ; the third conical; the flagellum small, two-jointed, with the 

 long hyaline filaments common to all the species of this family. 



Second antennce. Very slender ; the last joint of the peduncle is rather longer than 

 the penultimate; the flagellum consists of one short joint with several setae about thrice 

 as long as the joint. On one side of the specimen the flagellum is possibly two-jointed. 



Upper lip. The hairs on the distal margin are convergent. 



First maxillie. These show a small spinule in the position of the palp. This minute 

 character may be generic ; but in tlie other species only a sligiit bulge of the margin 

 has been perceived at the point in question. 



Maxillipeds. Inner plates Avith three or four apical spine-teeth ; the outer plates 

 rather large, minutely fringed on distal half of the inner margin ; palp only three-jointed, 

 and not quite reaching the ajiex of the outer plate. 



