8 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
An excellent account of the Samoan Reefs has been published by Dr. 
Kriimer,! supplementing the earlier short notice of Dr. Graeff* on the 
reefs of the group; also interesting notes by Admiral Wharton,® on Sub- 
marine 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”™ on what they call “ Patch 
Reefs,” 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 referred 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 part in the physiognomy of the coast. I am ata 
loss to understand the statements of Ortman regarding the reefs of 
Kaneohe Bay on the north shore of Oahu. The accurate observations of 
Hartt ® and of Rathbun 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 Rathbun 
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. 
8 Foundations of Coral Atolls, Nature, February 25, 1897, p. 390. 
4 On the Geology of the Tonga Islands, Quart. Jour. Geol. Soc. London, No. 188, 
1891, p. 890. ; 
5 Zool. Jahrbiicher, Bd. XI. p. 141. 
6 Proc. Acad. N. S. Phila., 1890, p. 3138. 
? Zool. Jahrb., Bd. VI. p. 682. 
8 Hartt, in Chapter IV. p. 174, of the Geol. and Phys. Geog. of Brazil, 1870, 
describes the islands and coral reefs of the Abrolhos and the Recife de Lixo, 
where exist the “ chapeirdes,” 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. 
10 Geology and Physical Geography of Brazil, Boston, 1870. 
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