CRUSTACEA PROM THE c CHALLENGER ' EXPEDITION. 47" 



of the African continent. This Cardisoma inhabits large holes all along the shore, 

 especially in the palm-groves on both sides of the town. But when I went there the next 

 day to catch more of them, the difficulties in getting them were too great ; for the holes 

 were more than 3 feet deep. The one, however, which Mr. Moseley had caught, a 

 female, proved to be very interesting ; for after having killed it in spirits, I found the 

 next day that its abdominal feet were covered with strings of eggs, that most of these 

 eggs were empty, some of them containing an embryo, and that among the empty eggs 

 there was a good number of young animals newly come out. These young ones, how- 

 ever, were not like their mother, but Zoeas. The greater number of them had evidently 

 left the mother already; some were still to be found among the empty capsules; and 

 others had not yet emerged. In fig. 3 Mr. "Wild has drawn me such a string of eggs 

 (each 0'42 millim. in diam., having the form of a grape), in which the berry-like 

 pedunculated eggs surround a common axis. 



The Zoea of Cardisoma (fig. 1) leaves the eggs in a somewhat more advanced state 

 than the Zoea of Carcinas meenas. If we compare it with the figures given by Mr. Spence 

 Bate (' Philosophical Transactions,' 1858, pi. xl.), we find that it represents a middle 

 stage between the larva of Carcinus meenas which has just left the egg and the one 

 after its first moult (figs. A and B). With the former it has in common the want of the 

 frontal spine, with the latter the presence of setse on most of the appendages, and the 

 more developed caudal fin. 



The carapace is very globular, and its dorsal spine is only small. The frontal spine, 

 entirely wanting now, is probably only developed after the next moult. The eyes are 

 very large. I could not see the pedunculus ; but as I had only dead animals before me, 

 which had been for some time in spirit, I do not deny that a very short pedunculus 

 might exist. The first antenna has a few more hairs than in the second stage of 

 Carcinus meenas; but the second ones are very much like each other in both cases (a 1 

 and a 2 , fig. 1). The parts of the mouth (m) had equally already got their hair. I had 

 some difficulty in getting a side view of them, and could have only isolated them with 

 very great difficulty, which was not worth while, as there was no chance of getting 

 later stages of this larva. The two gnathopoda have four long hairs in the last joint, 

 which in our case (gp l and gp 2 ) are not so long, and not feathered, as they are in the 

 second Zoea-stage of Carcinus meenas. I have not seen any buds of the pereiopods 

 behind those two legs, which are present in the young Carcinus meenas. 



Each segment of the pleon presents some black pigment spots, some of which were 

 also-observed in the carapace. There are no appendages on the pleon. The last segment 

 is bifurcate ; and at the inner side of the two terminal pieces six feathered setse may be 

 observed, very much like those in fig. 21" of Spence Bate's larva. 



I think there is no doubt that these Zoeas, as they partly had done already, leave the 

 mother and lead a pelagic life until they have undergone all their metamorphosis ; and 

 I hope that in other parts of the world which we are about to visit, I shall be able to 

 complete these observations on the propagation of the land-crabs, and to make out in 

 which genera there is a metamorphosis, and in which not. 



I may add here an observation which I made some years ago in Italy, and which, 



