SWAN PIUNCES ISLANDS. 61 



The rocks of the island may be divided into — (1) Primary sedi- 

 mentary strata, and (2) Trachytic rocks. 



(1.) The sedimentary rocks are chiefly confined to a thin band of 

 shales and sandstone around the northern coast of the island, much 

 metamorphosed by the action of the adjoining igneous rocks, and 

 interstratified in places with them. Fossil remains are extremely 

 rare in these beds ; an impression of what would seem to be a Go- 

 niatite, in brown shale, and a doubtful one of the stem of a plant, 

 are all that can be recorded: they are, however, sufficient to place 

 these rocks with the Devonian strata of Prinkipo, and are probably 

 of the same age in. the series. 



(2.) These strata are similar to the soft white feldspathic rocks in 

 the opposite coast of Prinkipo, and need, therefore, little further de- 

 scription here. The stone in general is less siliceous in its nature, 

 and approaches nearer to a pure kaolin than that of Prinkipo ; 

 the joints are also less impregnated with iron ; and I have not been 

 able to detect any great masses of iron-ore throughout the whole of 

 the island. 



In concluding the description of Chalki, I must not omit to remark 

 that at the extreme end of the beautiful little bay of Tchemliman 

 the trachytes are seen to be impregnated with green carbonate of 

 copper in minute veins, similar to those near Morton's Mill on 

 Prinkipo, 



5. Island of Petala or Peta. — There is nothing of importance, 

 geologically speaking, to notice respecting this island; the strata 

 are white trachytes, similar to those of Chalki. 



6. Island of Antigoni. — Antigoni may be said to be almost en- 

 tirely of volcanic origin, and is composed principally of soft white 

 feldspathic trachytes, coloured red in parts by the presence of iron. 

 There occur, however, on the north-eastern coast of the island, 

 variegated white and purple sandstones, and grey quartzose rocks, 

 which have every appearance of being stratified, and may probably 

 at some future time be classified with the sedimentary Devonian 

 rocks of the Island of Proti, which I shall now proceed to describe. 



7. Islaiid of Proti. — The physical features of Proti are sterile and 

 uninviting ; and in consequence this island is the least frequented by 

 the pleasure-seekers of the capital. 



The geological features, on the contrary, are exceedingly interest- 

 ing, exhibiting a series of strata entirely different from those of any 

 other of these islands (if we except a small portion of Antigoni, just 

 described), and forming another link by which to join together the 

 several detached portions of Devonian strata, of which the Princes 

 Islands are the remains. Here are to be seen, for the first time in 

 all my examinations (as well here as on the mainland), to any ex- 

 tent, red sandstones, as if to prove the relationship by colour, if not 

 by animal life, of the Turkish Devonian rocks to those of Hugh 

 Miller's Old Red Sandstone series of Scotland. 



The strata of Proti are entirely of sedimentary origin, arranged in 

 a basin- or troughlike shape, and composed of sandstones, highly 

 micaceous in part, of colours red, purple, white, and grey, associated 



