1 32 F P. BEDFORD [august 



locally common ; he might also see large Holothurians basking in the sun, 

 either stationary or crawling slowly over the mud, but the commonest 

 groups would be those that he was already accustomed to. Hermit- 

 crabs abound everywhere, and at night the shore will sometimes be 

 almost covered with them ; crabs and prawns shelter themselves in 

 crevices or under stones or in the sand, and Spatangids, Chaetopods, 

 and Gephyreans make their burrows in the sand or rocks ; limpets, 

 too, of a diminutive size it is true, but still obvious limpets, stick to 

 the rocks with the same tenacious grip as elsewhere, and obviously 

 fill the same place in the economy of nature ; our common littoral Gas- 

 teropod genera, such as Nassa, Purpura, Littorina, Trochus, etc., are 

 represented by forms closely similar both in form and habits, and 

 many of the species seem to have extremely variable coloration as on 

 our own coasts ; in fact it would be difficult to name any characteristic 

 difference. Polychaet tabes project from the surface on nearly every 

 sand-flat, Lamellibranchs abound in the mud and bore into rocks and 

 wooden landing-stages, Nudibranchs of brilliant colours, together with 

 Polyclads, creep about on stones and sea-weed, and even the abundant 

 Pcriophthalmus which forms so marked a feature of the littoral fauna 

 as it bounds over the surface of the pools, or rests on some adjacent 

 object just above the water, is after all only a goby, such as every boy- 

 naturalist delights to hunt at home. 



The conclusion thus seems forced on our attention that the broad 

 features of marine life, the modes of adaptation of different groups to 

 their inorganic environment, and the modes of life adopted in their 

 mutual rivalries of offence and defence, are to a very considerable extent 

 independent of geographical position or climatic influence, and what is 

 perhaps more surprising, they would seem to be independent of the 

 marked differences which undoubtedly exist among the higher verte- 

 brates. The presence of numerous kinds of tropical sea-birds, of sea- 

 snakes, of crocodiles, and of a host of curious fish seems to have made 

 a scarcely appreciable impression on the habits of the lower forms : 

 and from what we know of fossil fauna, commencing from the Olenellus 

 and other faunas of the earliest fossiliferous rocks which have retained 

 the imperfect relics of but a few of their once living inhabitants, it 

 might be surmised that from that time onwards these same broad 

 features have persisted all the world over, altered but slightly from 

 time to time by the subsequent evolution from some of them of the 

 Decapod Crustacea, Vertebrates, and other " higher " forms. No 

 doubt, too, in a similar way the exclusively tropical forms, among 

 which we may perhaps regard the reef-building corals as in this respect 

 the most important, have led to modification of the animals dependent 

 on them, but from a superficial point of view at least, the crabs, prawns, 

 Cirripedes, Lamellibranchs, and Holothurians that live associated with 

 them do not differ very considerably from their allies which are 

 surrounded by other environments. 



