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Show 938 MR. L. A. BORRADAILE ON THE PAGURINE LAND-CRABS. [Nov. 28, native, it is only what was to be expected. A " native," being unfamiliar with the idea of a metamorphosis, will always give the same answer to any question on the subject, namely that the young are born exactly like the adult-but very small. All doubt on this point has, however, now been removed by the discovery by Dr. A. Willey of a female Birgus on the rocks at the brink of the sea at Lifu in the Loyalty Islands. The abdomen of this specimen was covered with hatching zoaeas which were being washed off into the water. The time of the year was the month of January \ With regard to the genus Cosnobita, I have myself recently taken specimens of two species (C. rugosus and C. perlatus) in Ceylon and the island of Minikoi in the months of M a y and June, bearing zoseas. The animals were taken on the stretch of wet sand just above the waves. The catches of the tow-net in the island of Minikoi not having yet been examined for specimens of the zosea of Ccenobita, the possibility is not completely excluded that the larva? may undergo the whole or a part of their development within the shell of the mother, which is always wet with salt water. The larva?, however, did not, on a cursory examination, give any indication to justify such an assumption, and when placed in sea-water lived for a short time and showed powers of swimming in a lively manner. An attempt to rear them unfortunately failed, but this was only to be expected in view of the known difficulty of the operation. It is perhaps worth noticing that the above two species of Ccenobita are those whose habits keep them nearest to the sea. If an abbreviated development is to be found in the genus, it would more probably occur in forms such as G. spinosus which live at a considerable distance from, or at least a considerable height above, the sea. From the observations just recorded, it is clear that the early stages of the development of the Ccenobitidce present no very remarkable features. It may be presumed that later stages follow the ordinary course. The only points of interest remaining for investigation are the assumption of the adult form by Birgus and the transition from sea to land, which we may hope' to have described by some future traveller in the Pacific Ocean. 1 The present writer is under great obligation to Dr. Willey for banding over to him a number of these zoams, which will be described and figured in Part V. of Dr. Willey's " Zoological Results " now being published by the Cambridge University Press. It is intended also to publish an account of the larva? of Cernobita. |
