8 BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



An excellent account of the Samoan Reefs has been published by Dr. 

 Kramer/ supplementing the earlier short notice of Dr. Graeff- on the 

 reefs of the group ; also interesting notes by Admiral Wharton,^ on Sub- 

 mai-ine Banks of the Pacific. A careful account of the geology of the 

 Friendly Islands by Lister/ published in 1891, seems to have escaped 

 the attention of writers on coral reefs. A few notes on the reefs of some 

 of the islands of the Bismarck Archipelago have been published by Dr. 

 Dahl/ but the evidence he gives does not seem to me to warrant his 

 conclusions. The great thickness of elevated reef he found (570 m.) 

 may (as is the case elsewhere in the Pacific) not belong to the present 

 epoch, as he takes it for granted, and no one supposes that elevation has 

 necessarily always taken place uniformly either in time or space over 

 any great stretch of territory. 



The articles by Heilprin ® and by Ortman ' ou what they call " Patch 

 Eeefs," do not seem to me to have any special bearing on the general 

 theory of coral reefs. The existence of such " patches " has long been 

 known and refei'red to by Darwin, and by many writers on coral reefs, 

 as reef patches. These patches occur in localities where fringing reefs for 

 local causes would not flourish except at a little distance from shore and 

 play a very subordinate pai't in the physiognomy of the coast. I am at a 

 loss to understand the statements of Ortman regarding the reefs of 

 Kaneohe Bay on the north shore of Oahu. The accurate observations of 

 Hartt s and of Eathbun on the moderate thickness of coral reefs off the 

 coast of Brazil seem to have escaped Heilprin and Ortman, as well as other 

 writers on coral reefs. Rathbun ® has described the reefs along the 

 Brazilian shore, and finds them all as "having very little height, but 

 from the surface looking like massive structures." Hartt ■^'* and Eathbun 

 have described the formation of extensive coral patches and the mode of 



1 Ueber den Bau d. Korallenriffe, Kiel, 1897. 



2 Samoa, Journal d. Museum Godeffroy, Vol. I. 



3 Foundations of Coral Atolls, Nature, Februar\' 25, 1897, p. 390. 



* On the Geology of the Tonga Islands, Quart. Jour. Geol. Soc. London, No. 188, 

 1891, p. 890. 



5 Zool. Jalirbiicher, Bd. XI. p. 141. 



6 Proc. Acad. N. S. Phila., 1890, p. 313. 

 ^ Zool. Jahrb., Bd. VL p. 632. 



8 Hartt, in Chapter IV. p. 174, of the Geo!, and Phys. Geog. of Brazil, 1870, 

 describes the islands and coral reefs of the Abrolhos and the Recife de Lixo, 

 where exist the " chapeiroes,'" as rising straight up from the bottom from a depth of 

 forty to fifty feet. 



9 American Naturalist, Vol. XIII., June and September, 1879, Nos. 6 and 9. 

 1° Geology and Physical Geography of Brazil, Boston, 1870. 



