205 



stances have Bopyricls been observed on species of this genus of Anomura. One 

 of these forms has recently been described by Dr. Hansen as a type of a new 

 genus under the name of Munidion princeps; it was procured from a specimen 

 of Munida refulgens taken in the Pacific. The other form is recorded by M.M. 

 Girard and Bonnier under the name of Palcegyge insignis from the Mediterranean, 

 and is stated to infest Munida rugosa. It may be that this form will turn out 

 to be the same species as that here described; but as no description or figure 

 has as yet been given, it is impossible at present to state this with certainty. 



Gen. 4. PleiirOCrypta, Hesse 1865. 



Syn.: Phryxus, Sp. Bate & Westw. (part). 



Generic Characters. General form of body in female resembling that in 

 Pseudione. Cephalon broadly marginate in front. Segments of mesosome well 

 .defined, with the lateral parts, as in Pseudione, divided by a transversal groove; 

 coxal plates generally very largely developed and contiguous, forming sometimes 

 a broad marginal area flanking the sides of the mesosome. Epimeral plates of 

 metasome distinctly developed, and of different form in the different species. 

 Antenna? as in Pseudione. Terminal joint of maxillipeds imperfectly defined. 

 1st pair of incubatory plates with the distal segment securiform; the succeeding 

 pairs large, arching over the ventral face. Legs comparatively small, more or 

 less completely concealed beneath the coxal plates. Pleopoda biramous, with the 

 rami tuberculate or smooth. Uropoda forming 2 simple juxtaposed appendages, 

 as in Pseudione. Male of different form in the different species, segments of 

 metasome completely fused together. Parasitic in the branchial cavity of Ano- 

 mura belonging to the genera Galathea and Porcellana. 



PemarJcs. — This genus, established by Hesse, is undoubtedly very 

 closely related to Pseudione, and the only more essential characters by which it 

 distinguishes itself, is the fuller development of the coxal plates in the female, 

 and the fusion of the segments of the metasome in the male. The type of the 

 genus is PleurocryjAa galathea Hesse, found on Galathea squamifera. The 

 description and figures given of this form by Hesse, exhibit, however, so many 

 singular features unknown in other Bopyridse, that I should, indeed, have hesi- 

 tated in referring any of the Norwegian species to that genus, if the deplor- 



