15S BALANTDJE. 



cular membrane is not periodically moulted, that the mem- 

 brane lining the sack is not always thrown off at the same 

 exact time with that of the body. In Chthamalus stellatux, 

 in the act of moulting, the opercular membrane is the last 

 part that separates from the new underlying membranes : 

 1 find that this species can moult when kept in a damp 

 box out of water. The new membranes of the body, 

 immediately after the exuviation, are not lax in any extreme- 

 degree. The exuviae of the genus Chthamalus, and of sonic 

 other genera amongst the Chthamalinae, can at once be 

 recognised by the divergence of the posterior four pairs 

 of cirri : in the case of Chthamalus stellatus 1 have also noticed 

 that the animal generally dies with these cirri in the same 

 divergent position. Finally, I cannot doubt'" that the 

 Triton described by Linnaeus was only the exuviae of some 

 Balanus (probably B. porcatus) ; Linnaeus mistaking the 

 probosciformed penis for the mouth of his imagined distinct 

 animal. 



I have seen a few specimens showing that when the shell 

 has been broken it can be repaired ; and this I believe 

 is effected by the growth of a crest of corium between 

 the broken edges, and the subsequent calcification of this 

 crest. Mr. Stutchbury possesses a monstrous specimen of 

 Chelonobia testudinaria, in which one of the lateral com- 

 partments on one side has not been developed. The cirri 

 not rarely get cut off, but are, as it appears, soon repaired. 

 I have observed a singular number of examples of the act 

 of reparation in a group of the Australian Balanus vest li us. 

 The manner in which the cirri are repaired seems to me 

 curious : the cut-off end is closed by a rounded scale of 

 yellowish chitine, and then the corium, in the four or five 

 subjacent segments, separates from the external articulated 

 membrane, which now serves only as a case or capsule. 

 The tube of corium thus enclosed, with its contained muscles, 

 shrinks a little, and soon can be perceived to be in process of 



* Linnseus speaks of the included body (inhabitant as he calls it) of other 

 Cirripedes, as a Triton ; and this, I think, shows that Lesson's conjecture that 

 the Triton was an Alepas cannot be correct ; for Linnaeus could hardly have 

 supposed that a pedunculated cirri pede inhabited another pedunculated or 

 sessile cirripede. 



