GEOGRAPHICAL DISTRIBUTION. 341 
Rapa, have coral reefs fringing the shores. There is no evi- 
dence of recent volcanic action among them. Some of them 
are elevated coral islands, as Mitiaro, Atiu, Mangaia and 
Mauki, and also, according to Stutchbury, Rurutu. Oka- 
tutaia is a low coral island but six or seven feet out of 
water. ‘ 
Between the Paumotus and the longitude of Samoa are 
numerous small islands, all of coral origin. 
The Samoan or Navigator Islands have extensive reefs, 
About Tutuila, owing to its abrupt shores, they are somewhat 
less extensive than around Upolu, and about Savaii they are 
still smaller, as already explained. The influence of abrupt 
shores may also be seen in some parts of Upolu; for example, 
to the west of the harbor of Falifa, where, for several miles, 
there is no reef, except in some indentations of the coast. 
Manua is described as having only shore reefs. 
The Tonga Islands, south of Samoa, for the most part 
abound in coral reefs, and Tongatabu and the Hapai Group 
are solely of coral. Hoa is a moderately high island, with a 
narrow reef. ‘Tafoa an active volcano, and Kao, an extinct 
cone, are without reefs. Vavau, according to Williams (M/s. 
Enterprises, p. 427, Amer. ed.), is an elevated coral island. 
Pylstaarts, near Koa, is a naked rock, with abrupt shores, and 
little or no coral. Sunday Island, farther south (29° 12’S.), 
is beyond the coral-reef limits. 
North of Samoa are the Union group and other islands of 
small size, all of coral. 
/ The Feejee Group, already sufficiently described, abounds 
in reefs of great extent. There are no active volcanoes, 
and, where examined, no evidence of very recent volcanic 
action. The many islands afford a peculiarly favorable re- 
gion for the growth of zodphytes, and the displays of reefs 
