168 BULLETIN OF THE 



erful enough on the beach itself to throw up huge masses of Pontes, of 

 Pocillopora, and of Astrseans, and with them a large number of shells 

 living on the reef. The whole is pounded by the process iuto a sort 

 of coquina, which is cemented on the beach, much like coral breccia. 

 Owing to the steady action of the trades, the finer sands accumulated 

 on the beach would be blown up the slope and carried off to form the 

 travelling dunes, or the masses of drifting coral sand carried inland to 

 form the coral sand drifts, while quite heavy fragments were also blown 

 up bodily to the upper level of the beach. 



Kahului ELiy is sheltered by a wide, flat, active coral reef, the harbor 

 being an inlet of the western and widest end of the reef. The reef ex- 

 tends easterly, gradually becoming narrower toward Paia, where it ends. 

 Only occasional patches of corals are found to the eastward of this point. 

 It is this extensive coral flat, covered with huge masses of Pontes and 

 Pocillopores, upon which the full force of the trade-wind sea is pounding, 

 which furnish many of the larger blocks of the Maui coral coquina 

 which were left as formed in sheltered places, and were covered by 

 a luxuriant growth of a species of Sargassum ; the surface of many 

 of these blocks was protected by masses of Nullipores and other calca- 

 reous algse. The Kahului beach is broken by numerous spits extending 

 out on the reef. These spits are remains of lava flows which have be- 

 come covered with huge rounded masses of lava, and in part by frag- 

 ments of broken coral and by coral sand, sometimes one to two feet in 

 thickness. In this breccia and conglomerate, as well as in the stratified 

 coral coquina formed in its proximity, numerous rounded and water- 

 worn pebbles of lava have become imbedded. The coral lava conglom- 

 erate thus formed has a most striking appearance. I had been greatly 

 puzzled by finding similar deposits inland near Maalaea Bay, on the low 

 plain extending towards Kahului, and on some of the sugar plantations 

 at a distance to the east from the road connecting the above-named 

 places. 



The recent British Admiralty Chart, No. 1520, shows very well the 

 distribution of the coral reefs of the Sandwich Islands. The only 

 islands which I examined for reefs myself are Oahu, Maui, and Hawaii, 

 and in passing close to the south shore of Molokai I could readily see 

 from the color of the -water that there was an extensive fringing coral 

 reef. 



Cambridge, November, 1888. 



