CONTENTS. 



PART I. 



CHAPTER I. 



ST. JAGO, IN THE CAPE DE VEEDE AECHIPELAGO. 



Hocks of the lowest series — A calcareous sedimentary deposit, with 

 recent shells, altered by the contact of superincumbent lava, its 

 horizontality and extent — Subsequent volcanic eruptions, asso- 

 ciated with calcareous matter in an earthy and fibrous form, and 

 often enclosed within the separate cells of the scoriae — Ancient 

 and obliterated orifices of eruption of small size — Difficulty of 

 tracing over a bare plain recent streams of lava — Inland hills of 

 more ancient volcanic rock — Decomposed olivine in large masses 

 — Feldspathic rocks beneath the upper crystalline basaltic strata 

 — Uniform structure and form of the more ancient volcanic 

 hills — Form of the valleys near the coast — Conglomerate now 

 forming on the sea beach PAGE 3 



CHAPTER II. 



FEBNANDO NOEONHA ; TEECEIEA ; TAHITI, ETC. 



Fernando Noronha — Precipitous hill of phonolite. Teeceiba — 

 Trachytic rocks ; their singular decomposition by steam of high 

 temperature. Tahiti — Passage from wacke into trap ; singular 

 volcanic rock with the vesicles half rilled with mesotype. Mau- 

 ritius — Proofs of its recent elevation — Structure of its more 

 ancient mountains; similarity with St. Jago. ' St. Paul's 

 Eocks — Not of volcanic origin — their singular mineralogical 

 composition 27 



