EEPORT ON THE AMPHIPODA. 871 



ParamjjJiithoe should be classed among the Ejaimeridse, and that he has "seen fit to 

 retain Spence Bate's genus Pleustes for P. payiopla, Kroyer, and the species nearest 

 related to that form." He does not, however, say whether he places Pleustes also in the 

 family Epimeridse. For the original definition of the genus, see Note on Spence Bate, 

 1858 (p. 308). Boeck gives the following more expanded description : — 



" Upper Lip> deeply cleft. 



"Mandibles unlike one another ; one with, the other without, an accessory plate ; the 

 third joint of the palp almost equalling the second in length. 



" First Maxilla; having the outer plate furnished with slender spines, some of them 

 serrate on the inner margin, some apically furcate ; the palp apically furnished with 

 spines ; the inner plate small, with few setae. 



" Maxillipeds with the inner plate short but broad ; the outer plate small, with 

 slender spines on the inner margin ; the palp elongate, its last joint forming a long nail, 

 serrate on the inner margin. 



" Upper Antenme longer than the lower. 



" First four pairs of side-plates large or of moderate length and successively 

 larger. 



" Head produced into a frontal rostrum, which is generally strong. 



"First and Second Gnathopods more or less robust, of nearly the same shape; the 

 wrist short, sending out a small heel from the lower hinder angle. 



" Uropods with the outer ramus shorter than the inner. 



" Telson small, undivided." 



To this he appends the remark in brackets, that " the genus Pleustes can scarcely 

 be included in the Oedicerinse." ' Accordingly, at p. 496 of the work just quoted, he 

 places the genus Pleustes among the Leucothoinse, the sixth subfamily of the Leuco- 

 thoidse, without, however, noticing that his definition of this subfamily disagrees in some 

 respects with his generic definition of Pleustes. Thus, in describing the side-plates of 

 the Leucothoinse, he says, " Imo majore qvam 2do et 3tio," of the uropods he says, 

 " ramis ultimi paris longitudine fere sequalibus," and of the telson, " appendix caudalis 

 elongata." 



The new species here assigned to the genus diflPers from Boeck's generic account in 

 having a secondary plate on each mandible, and in having the thii-d joint of the 

 mandibular palp longer than the second, in that particular, however, agreeing with 

 Boeck's own, as well as Schneider's, specific account of Pleustes panoplus, Kr0yer. 



