Whether there are in this part of Melanesia any atolls properly so called may be a question. There are lagoon islands of two kinds. The Reef Islands of the Santa Cruz group show flat patches of sand and coral resting on the reefs; such a one is Nukapu, where the lagoon is two miles across. The Matema group, part of the same Swallow group, consists of several sand islets resting on the edge of a very large and irregular reef; two of the islets, which are only separated at high tide, are very characteristically inhabited, Nufilole by a score or two of Melanesians, and Fenua loa, as the name imports, by Polynesian colonists from the East. On the other hand, Rowa in the Banks' group consists of five tiny islets on the bight of an irregular reef five miles long, the principal islet being formed upon a jagged point of volcanic rock, to all appearance a fragment of the edge of a sunken crater.
The Tas in the middle of Santa Maria in the Banks' Islands is the only lake of considerable size known in Melanesia. It is about five miles long, occupying the hollow of the ancient crater, into which the steaming hill Garat has been intruded; the waters pour out in a magnificent waterfall. There is a much smaller lake in Vanua Lava which feeds two fine cascades, and another on Lepers' Island with a volcanic vent upon its edge. Bishop Selwyn in 1888 found the lake at Tikopia covered with large water-lilies; the Tas of Santa Maria will surely reward its first scientific visitor.
A few words may be ventured on the natural history of this part of Melanesia. The cuscus common in the Solomon Islands does not reach to Santa Cruz; it is believed to exist in Espiritu Santo, where Quiros reported that there were goats. The white cockatoo, abundant in the Solomon Islands generally, does not pass the two straits that separate respectively Guadalcanar and San Cristoval, Malanta and Ulawa; but while Ulawa does not strike the unlearned visitor as different in its zoology from Malanta, the birds of San Cristoval seem few and strange. Frogs stop short of Santa Cruz, abundant as they are in the Solomons. A remarkable megapod is found in all the groups, if not of more than one species at any rate with
