

Prof. T. Fuchs on the Deep-sea Fauna. 13 



and exactly similar species are known from the American 

 caves. Moreover the case is precisely the same with the blind 

 Isopod genus Cecitodcea, which occurs both in the great depths 

 of the Lake of Geneva and in the American and Carniolian 

 caves *. Among the most abundant and characteristic of 

 deep-sea fishes are those near allies of the Gradidae, the Opbi- 

 diidse ; and among them several blind species occur. Now it 

 is certainly very remarkable that two blind Ophidiiche, showing 

 the closest resemblance to their relations of the deep sea, are 

 found in the caves of Cuba. 



According to Moseley the corals of the Bermudas show a 

 remarkable sensitiveness to light. The great brain corals 

 (Diplosia cerehiformis) grow by preference in the bright 

 sunshine; Alillepora ramosa and Sympltyllia dipsacea prefer 



the shade ; and the extremely delicate white Mycedium fragile 

 occurs in great abundance in the beach-region, in the interior 

 of cavities. The genus Mycedium , which is here found in 

 the beach-region in the interior of cavities, and therefore ap- 

 parently in darkness, is, however, properly a deep-sea genus, 

 which otherwise occurs only at great depths. 



According to Falkenberg, Algae occur near Naples in a 

 dark grotto at a very small depth, which elsewhere are found 

 only at greater depths at the lower limit of Algae. j\ 



1 have no doubt that these examples will be greatly mul- 

 tiplied if only more attention be paid to these conditions ; and 

 I would warmly recommend the study of this question to all 

 naturalists who are in a position to make pertinent observa- 

 tions %. 



Here, however, I would notice a second question nearly 

 related to the preceding. It is well known that a number of 

 littoral animals penetrate in depth far beyond the limits of 

 the true littoral region, nay, that there are some species (es- 

 pecially of JEchinoderms and Vermes) which are found at all 

 depths, from the beach to 2000 fathoms and more. It would 

 certainly be interesting to examine whether these animals of 

 extraordinary bathymetrical distribution are not perhaps noc- 

 turnal animals in the littoral region, hiding themselves during 

 the day in dark places, or shutting themselves up in their 



* According to Cope and Packard the so-called Asellus Borelli of the 



Lake of Geueva belongs to the genus Cecidotcea (" The Fauna of the Nick*- 



jack Cave," Amer. Nat. 1882, p. 877). 



t See Dodel-Po8t, 4 Illustrirtes Ptianzenleben/ Zurich, 1880 (Marine 



Algae). 



X Fries has already called attention to the resemblance between th 

 deep-sea and cave faunas ; see "Die Falken-teiner Hohle, ihre Fauna 

 und Flora" (Wiirtteinb. Jahreshefte, xxx. 1874} p. 162). 



