LAND CRUSTACEANS. 91 



the same main features but is simplified by the absence of its numerous small denticula- 

 tions. The first antennae are simple, unjointed structures with a few hairs at the free 

 end. The second antennae have a large scale with a tooth at the outer angle and feathered 

 bristles along the inner edge. The endopodite is unjointed. The first maxilla has a jointed 

 palp, two stout feathered spines, and a broad gnathobase. The second maxilla is not much 

 removed from the adult form. The first two maxillipeds are the swimming organs and 

 have long, jointed endopodites and exopodites, bearing hairs. 



In every respect the larva has a typical Pagurine organization, but resembles Birgus 

 more nearly than the Pagurids. It differs from Birgus in: (1) its smaller size; (2) the 

 arrangement of the bristles of the telson, which in Birgus are of nearly equal length ; 



(3) the greater length and slenderness of the side spines of the fifth abdominal segment ; 



(4) the greater simplicity of the mandible. 



ix. Notes on the habits'. 



A circumstance which makes the habits of Coenobita somewhat more easy of investi- 

 gation than those of other hermit-crabs, is that almost the whole of their life is spent 

 on land. It has already been remarked- that the animals are rarely to be found in the 

 water, but we must at the same time admit that this question is far from being disposed 

 of. Their organization seems well adapted for a stay under water, and they may be proved 

 experimentally, as we shall see, to have the power of living for some time in that medium, 

 though it eventually proves fatal to them. 



According to Hughes' C. diogenes is "often found cleaving to rocks in the sea" and 

 " sometimes it is caught upon the rocks at a considerable distance from land." Again, 

 in Minikoi, the shells of many examples of C. rugosus and C. perlatus contained considerable 

 quantities of salt-water, and that in both sexes and irrespective of the caiTying of eggs 

 by the females. On the other hand Catesby* does not "remember to have seen any of 

 them (C diogenes) go into the sea," Ortniann* states that, out of hundreds of examples 

 observed by him in East Africa, not one was found in the water, and, with a single 

 exception", the same was the case in Minikoi. Moreover, in the case of species found at 

 a considerable distance from the sea', frequent visits to salt water are out of the question. 

 C. rugosus, C. perlatus and, according to statements*, C. diogenes undoubtedly go down 

 to the sea, when their young are hatching for the purpose of washing them off. Should 

 they be proved to frequent the water at other times, it will be interesting to discover 

 whether this be in connection with their breathing arrangements', or merely for some such 

 purpose as obtaining a favourite food or escaping an enemy, and further whether it take 

 place by night or by day". 



With regard to the food of Coenobita, there is not much that can profitably be said. 

 Their staple is, in Minikoi at least, the fruit of the Pandanus, but they are like many 



' Broderip [ZooL/oHCH., IV. p. 205] and Ortmann[Bronn's ' Such as C. spinosus, see Borradaile, P. Z. S., 1898, 



Thierreich, v. 2, pnnsim] quote passages from various authors p. 459. 

 on the subject of the habits of Coenobita. ' Quoted by Broderip [Zool. Journ., iv. p. 205] from the 



2 See above, p. 85. old " Encyclop^die " [Paris, 1751]. 



^ Hughes, Nat. Hist. Barhadoes, p. 265. ^ In order to moisten their gills etc. See above, p. 85. 



* Catesby, Nat. Hist. Carolinas, ii. p. 33. '" For some remarks on the same problem with regard to 



' Ortmann, Bronn's Thierreich, v. 2, p. 1183. Birgus, see Borradaile " Willey's Zool. Results," v. p. 585. 



" See above, p. 85. 



12—2 



