Subsided space at Ascension.

Tahiti.

Talus, stratified, within tuff craters.

Terceira.

Tertiary deposit of St. Jago.

Trachyte, absent at the Galapagos archipelago. -at Ascension. -at Terceira. -decomposition of, by steam. -its lamination. -its separation from basalt. -softened at Ascension. -specific gravity of. -with singular veins.

Trap-dikes in the plutonic series. -at King George’s sound.

Travertin at Van Diemen’s land.

Tropic-bird, now rare, at St. Helena.

Tuff, craters of. -their breached state. -peculiar kind of.