MUSEUM OF COMPARATIVE ZOOLOGY. 165 



they dam the outfet by throwing up a high sand dam ; this breaks 

 through when the water has accumulated a sufficient head. Half a mile 

 beyond Waimea the coral caps the lava beds at a height of nearly ten 

 feet above the high-water mark. 



At one other point two miles beyond Waimea, towards Waialua, we 

 find numerous coral tables capping lava bases. Many of these coral 

 tables are blocks ten by twenty feet, one of them as much as fifty by 

 one hundred feet. The height of the lava supports is usually five or 

 six feet. This elevated coral reef, all the way from Kohuku to Waialua, 

 is cut by lava spits, which project beyond its surface and extend sea- 

 ward. At Waialua there is a very fine patch of the elevated coral reef, 

 from five to six feet above the level of the sea. Traces of this reef can 

 be seen for five or six miles to the southward of Waialua, along the 

 beach, made up of coral sand mixed with more or less lava sand, which 

 I'eaches towards Kaena Point. 



As will be seen on examining Plate I., the reefs of Hawaii consist only 

 of isolated patches of limited extent near Hilo. On the sides of Upolu 

 Point, both east and west, isolated patches have been observed, near 

 Kawaihae, and at the southernmost point of Hawaii somewhat larger 

 stretches of coral exist. 



The so-called coral reef to the south of Hilo (Plate I.), near Keokea 

 Point, consists mainly of detached patches of corals (Pocillopora). They 

 are very much like the patches of corals to be found on the west coast 

 of Mexico, and do not constitute a regular reef, although a good deal 

 of coral grows in this way, judging from the amount of coral sand and 

 fragments thrown upon the small beaches to the south of Hilo. The 

 patches are mainly the same species of Porites and Pocillopora which 

 form the reef of Honolulu. There is comparatively little animal life on 

 these coral patches, and the lava rocks off" Hilo do not appear to support 

 a rich fauna. Although small algse grow thickly on the rocks, no Sargas- 

 sum was found attached, as near Waikiki on the Honolulu reef, and 

 on the coral conglomerate of the Spreckelsville beach on the north shore 

 of Maui. 



Near the northern extremity of Hawaii, near Honoipu, there is a 

 patch of coral and another patch to the eastward of Mahukona, clearly 

 seen from the railroad running round the northern point of Hawaii. On 

 the lee side of Hawaii there is, near the village of Kawaihae, a stretch 

 of coral reef, which protects a ba}' once a great resort of whalers. The 

 village itself is prettily situated at the northern end of a long coral 

 sand beach. To the south extend, as far as the eye can reach, the 



