80 Miscellaneous. 



Miiller has made known a Phryams of the Brazilian coast (Phryxus 

 resupinatus) which constantly attaches itself to hermit-crabs infested 

 by Peltogaster piirjoureus, and often upon the very peduncle of that 

 Ehizocephalan, If we accept the hypothesis of the inoculation of 

 the larvae of Rhizocephala put forward by M. Y. Del age, it would 

 therefore be necessary to suppose that the larva of Phryxus resupi- 

 natus divines which are the hermit-crabs inoculated with an embryo 

 Peltogaster, and the precise place at which this embryo will emerge 

 from the abdomen of the hermit-crab. We can escape from this 

 curious conclusion only by assuming, ixpon a still more curious 

 hypothesis, that the embryos of Phryxus themselves are also inocu- 

 lated and follow the larvae of Peltogaster in their internal migration. 

 Who would accept such a complication ? On the other hand, aU 

 becomes simple on the theory of direct fixation, and we may find in 

 the new facts above described a confirmation of the opinion expressed 

 by us, that in the phylogenetic series the Cirripedes have been the 

 introducers of the Bopyridae among the Decapod crustaceans. The 

 Isopods, originally parasitic upon the Rhizocephala, have infested 

 the higher crustacean, at first indirectly, but afterwards directly. 



I have endeavoured to extend the observations relating to para- 

 sitic castration to other Decapods, but unfortunately the materials 

 for such an investigation are difficult to get together. Notwith- 

 standing my great desire to do so, I have as yet been unable to 

 examine male CalUanassce infested either by Parthenopea suhterra- 

 nea or by Io7ie thoracica. Although Gehia stellata, Montagu, is 

 abundant at various parts of the coast of Prance (especially at Con- 

 carneau), I have never found on our shores the parasitic Eopyrid of 

 that species, Gyge branchialis, Cornalia and Panceri. I possess a 

 single example of an infested Gebia, which came from the Labo- 

 ratory at Naples. This specimen, however, is a male, and I have 

 been able to ascertain that it presents the first pair of simple abdo- 

 minal feet which normally exists only in the female ; the chela of 

 the first pair of thoracic feet has remained stronger than in the 

 females. Nardo, who observed in a locality where Gyge branchialis 

 is abundant, says that he has sometimes found the first abdominal 

 appendage in both sexes :■ — " lo posso assicurare pero che di tali 

 appendici poste una per lato sotto il primo anello dell' Addome, va 

 pure foruita la femmina, ed essere anche vera che talvolta ne sono 

 entrambi sprovvedati " *. It is probable that these abnormal males 

 were or had been infested by Gyge. 



The Brachyura infested by the Bopyridae of the genus Cepon 

 (Pilumnus hirtellus and Xantho Jloridus) and examples of Porcellana 

 longicornis infested by Pleuroeryptus Porcellance have presented no 

 appreciable modification of the external sexual characters. — Comptes 

 llendus, April 18, 1887, p. 1113. 



* Nardo, ' Annotazioni illustranti 54 specie di Orostacei,' Venice, 1869, 

 p. 100. 



