164 Miscellaneous. 



On the Metamorphosis of Praniza into Anceus. 



lu a recent Number (No. 6 of the present Series) we gave a very 

 brief notice of the reported discovery Ijy M, Hesse of Brest, that the 

 Pranizce are the larval forms of Anceus. At the meeting of the 

 Academy of Sciences on the '28th of June, 1858, M. Milne-Edwards 

 presented a report upon the memoir of M. Hesse, containing some 

 further information as to the extent of the observations made by the 

 latter. From this it appears that M. Hesse found some Pi-anizce 

 upon the fins of Gurnards and some other fishes, and kept them alive 

 in sea-water. After they had passed a few days in captivity, he saw 

 them become transformed into Ancei. In another series of observa- 

 tions M. Hesse followed the development of the ova deposited by 

 Ancei, and saw Pranizce hatched from them. "The fact of the 

 specific identity o{ the Praniz^B and Ancei," says M. Milne-Edwards, 

 "appears to us therefore completely established. The Prmiizee are 

 Ancei in the state of larvae, just as the tadpole is the young of the 

 Frog, and the silkworm the first state of the Bombyx." This memoir 

 of M. Hesse, with another by the same author upon the Caligidce and 

 Lernceadce, will be printed in extenso in the ' Memoires des Savants 

 Etrangers.' — Comptes Renclus, June 28, 1858, p. 1258. 



On the Power of Dissolving Shells jiossessed by the Bernard Crab 

 (Pagurus). By Dr. J. E. Gray, F.R.S. &c. 



In a note to my paper " On the Formation and Structure of 

 Shells," in the 'Philosophical Transactions' for 1833, I stated it is 

 probable that some Bernard Crabs have also the faculty of dissol- 

 ving shells, for it is not unusual to find the long fusiform shells 

 (such as Fusus fasciolanus and turbinella) which are inhabited by 

 these animals, with the inner lip and great part of the pillar on the 

 inside of the mouth destroyed, so as to render the aperture much 

 larger than usual. 



Having continued my observations on these shells, I am convinced 

 that certain species of Bernard Crab (Paffurus) have this power, some 

 possessing it to a much greater degree than others. 



Lieut. Burnaby lately brought a number of Crustacea to the 

 British Museum from the South Seas, amongst which there were 

 several specimens of Paguri in shells, and these shells were more 

 destroyed than any I had before observed. One, a specimen of 

 Persona tuberosa, not only had the whole of the thickened rounded 

 inner lip, but the whole of the septa between the whorls up to the 

 apex of the shell also destroyed, so as to convert the shell into 

 a simple conical cavity ; and the greater part of the substance of the 

 outer lip was also removed from the inner surface, so as to render 

 the outer jjart of the shell very thin — indeed so much was removed, 

 that the series of pits on the outer surface, just above the marginal 

 varix of the outer lip, was entirely destroyed, converting the pits 

 into a series of ajoertures. The other shells inhabited by these 

 Crustacea were similarly destroyed. The internal surface of the 

 shell has the appearance of being ground away by a file or other 

 rough surface. — Proc. Zool. Soc. March 9, 1858. 



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