126 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
undulating elongated ridge with conspicuous summits (volcanic ?), one of 
which is over six hundred feet high; it is a little over six miles in 
length, and situated at the northwestern extremity of an elongated 
plateau extending fifteen miles in a southeasterly direction, with an ay- 
erage depth of thirty to over forty fathoms. The western extremity of 
Thikombia, as well as the southern half of the island, is bordered by a 
fringing reef, which extends in a long spit made up of patches and 
detached rocks for two and a half miles in a southeasterly direction. 
Gardiner states that parts of Thikombia are terraced. 
Ono i lau. 
Plate 17°, Figs. 13-16, and Plate 23°, Figs. 1-4. 
We did not visit the islands to the south of Ongea. Among them 
are the Ono i lau Islands (Plate 1), of which some are volcanic and 
others composed of elevated coralliferous limestone, the highest island 
being 370 feet high. ‘These islands are surrounded by an outer reef 
flat, elliptical in outline, about seven miles by four, which is dotted 
with islets, rocks, and coral patches. To the south of these islands are 
the small islands of Tuvana i tholo and Tuvana i ra (Plate 17%, Fig. 
13, and Plate 23%, Fig. 27), situated on the northern edges of the 
circular barrier reef which surrounds them. To the southwest of the 
Ono cluster lies Vuata Ono (Plate 17%, Fig. 14, and Plate 23*,Fig. 3), 
an oblong reef nearly three miles long and always awash. Turtle 
Island to the northeast of Ono is a narrow ridge of elevated limestone, 
rising to over two hundred feet, with a barrier reef about four miles 
long off the west face, enclosing a narrow lagoon with six fathoms of 
water and passing into a barrier reef on the east face. Vuata Vatoa 
(Plate 23°, Fig. 4) is a detached reef somewhat over two miles in its 
greatest length, enclosing a tidal basin into which there is a boat passage 
through the reef. This reef lies about two miles to the south of Vatoa, 
with two hundred and forty-six fathoms in mid‘channel. Vatoa and 
Vuata Vatoa are probably the summits of a short ridge. The presence 
of elevated coralliferous limestone in this part of Fiji shows that the 
area of elevation of the group extended to the southernmost islands. 
Viti Levu and Vanua Levu. 
Plates 3, 3°, 4, 18. 
Although there are large stretches of the shores of Viti Levu and of 
Vanua Levu (Plates 3, 3°, 4) which I have not examined, we may per- 
