Sect. III. 



REEF-BUILDING COBALS LIVE. 



115 



sediment or by their own rapid growth. We have, 

 moreover, no right to calculate on unlimited time for 

 the accumulation of small organic bodies into great 

 masses. Every fact in geology proclaims that neither 

 the dry land nor the bed of the sea retains the same level 

 for indefinite periods. As well might it be imagined 

 that the British Seas would in time become choked up 

 with beds of oysters, or that the numerous small coral- 

 lines off the inhospitable shores of Tierra del Fuego- 

 would in time form a solid and extensive coral-reef. 1 



1 1 will here record the few facts which I have been able to collect 

 as to the depths, both within and without the tropics, inhabited by 

 those corals and corallines which we have no reason to suppose ever 

 materially aid in the construction of a reef. Mr. Stokes also showed 





Depth 



COUNTRY AND 





NAME OP ZOOPHYTE. 



hi 





AUTHORITY. 





fathoms. 



S. LATITUDE. 





Sertularia .... 



40 



Cape Horn 6 6° 



[Where none is 



Cellaria 



ditto 



ditto 



given the ob- 



„ A minute scarlet en- 







servation is 



crusting species, found 







my own.] 



living 



190 



Keeling At. 12° 





,, An allied, small stony 









subgeneric form . 



48 



S.CruzKiy.50° 





A coral allied to Vincularia, 









with eight rows of cells 



40 



Cape Horn 





Tubulipora, near to T. patina . 



•ditto 



ditto 





Do. do. 



94 



East Chiloe 43? 





Cellepora, several species and 









allied sub-generic forms 



40 



Cape Horn 





Ditto • 



40 

 and 

 57 



1 ChonosArch. 

 | 45° 





Ditto ...... 



48 



S. Cruz 50° 





Eschara 



30 



j Tierra del 

 1 Fuego 53° 





Ditto 



48 



S. Cruz R. 50° 





Eetepora . . . 



40 



Cape Horn. 



( Quoy andG-ai- 



Ditto 



100 



j C. Good Hope 

 I 34° 



1 mard. Ann. 



] Scien. Nat, 



I { t. vi. p. 284. 



i 2 



