280 CALMAN. 



are satisfactorily accounted for. In either case the pair iv prob- 

 ably represent the maxillipeds, the minute bifurcation at the tip 

 recalling the biramous character of these organs in the embryos 

 of Cancrion and of Ccpon (Giard and Bonnier, Bopyriens, PL 

 III, f 6 and 7). 



The completely segmented abdomen of both sexes, the bira- 

 mous pleopods of the female and the presence of rudimentary 

 pleopods in the male, would refer this species to the genus 

 Palcegygc as established by Giard and Bonnier in i888 (Bull. 

 Scient., XIX, 63). The fact that the species infests a pagurid, 

 and the rugosity of the pleopods in the female would place it in 

 the second division of that genus recognized by these authors in 

 1890 (Bull. Scient., XXII, 373), to which, adopting Stebbing's 

 suggestion (Hist. Crust., 411), we may apply the earlier name 

 PseudionL\ Kossmann. Of the species enumerated by Mr. Steb- 

 bing as referable to the latter genus, three ; P. Fraisci (Koss- 

 mann), P. DoJirni (G. & B.), P. insigiiis (G. & B.), appear to be 

 noniina luida, regarding which no particulars save the names 

 of their hosts are recorded. Of P. callianasscE Kossmann, only 

 the male appears to be described, and from the account given 

 by Kossmann (Z. f W. Z., XXXV, 663, PL XXXIII, f 37), 

 and reproduced by Giard and Bonnier (Bopyriens, pp. 77-8), 

 we learn that that species agrees with our form in the presence 

 of rudimentary maxillipeds in the male, though these rudiments 

 are very much smaller in Kossmann's species than in ours. 

 Moreover, rudiments of the first maxillae, which we have not 

 found, are figured as present in that species. 



In Psciidionc Hyiidnianni (Bate & Westwood), described in the 

 British Sessile-eyed Crustacea (p. 243), as PJiryxiis Hyndnianni, 

 from Eiipagiinis bcmiJiardiis (L.), the general features of the fe- 

 male appear to approximate very closely to our species. The 

 pleural lamellae of the abdomen, however, appear to be rounded 

 instead of pointed, and those of the last segment are shorter and 

 broader. The pleopods are smaller and less unsymmetrical. 



In Psciidionc coiiftisa (Norman), from GalatJica dispcrsa Bate, 

 described in the above mentioned work (p. 249) as PJiryxus 

 galathcce, the brief description and imperfect figures of the fe- 



