14 Prof, T. Fuehs on the Deep-sea Fauna. 



shells, and going about the business of their lives only at 

 night. Should this be proved, we shall have in strictness 

 to regard such animals not as littoral animals which penetrate 

 to unusual depths, but, from their nature, as deep-sea animals 

 which ascend exceptionally into the lighted regions, but here 

 keep themselves concealed during the day, and display their 

 vital activity only at night. 



That the Cephalopoda are chiefly nocturnal animals is well 

 known* The great importance that what has been brought 

 forward in the preceding pages must have for the geologist 

 and the palaeontologist especially is at once evident. 



On the coast of Brazil, according to Dana, the construction 

 of the coral-reefs is completed in a very peculiar manner. 

 The coral-stocks grow up from a depth of 6-8 fathoms in the 

 form of columns, and then widen out at the top, like an um- 

 brella. In course of time the umbrella-like widened parts of I 

 the neighbouring columns unite laterally ; and thus there is 

 finally produced an extensive roof of coralline limestone, 

 which rests upon numerous vast columns, and has under it 

 extensive dark catacomb-like spaces* Similar extensive laby- 

 rinthically branched systems of caverns are described by 

 Klunzinger also in the coral-reefs of the Red Sea ; and, ac- 

 cording to Dana, extended branching caves are a perfectly 

 ordinary phenomenon in the coral-reefs of the Pacific Ocean. 

 If, therefore, the preceding hypotheses are correct, a fauna of 

 the character of the deep-sea fauna must occur in these sub- 

 marine cavities of the coral-reefs ; and if we imagine these 

 caverns in course of time filled with the remains of these par- 

 ticular animals, together with material washed into them, and 

 then imagine these coral-reefs subsequently upheaved, a future 

 geologist in investigating such a reef would find nests of deep- 

 sea animals in the midst of the littoral reef-limestone, and be 

 considerably embarrassed thereby. 



I may here notice a phenomenon to which Suss has called 

 attention in his well-known work on the Brachiopoda of the 

 Kossen beds. Suss states that the so-called Stahremberg 

 beds, which consist of an accumulation of certain small Bra- 

 chiopoda, always occur in the form of isolated nests in the 

 Dachstein limestone ; and he further adds that these nests 

 are at the same time distinguished by their red colour from the 

 white Dachstein limestone. The white Dachstein limestone 

 with its great Megalodonts, however, is undoubtedly a shallow- 

 water formation, produced after the same fashion as our 

 present coral-reefs, while the fauna of the Stahremberg beds 

 bears the character of a deep-sea formation. If we imagine 

 that the Dachstein limestone was actually a reef, and that this 





