178 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 17, 



above referred to ; and I now continue the observations from the 

 town of Chalcis, at the central portion of the western coast of Euboea. 

 This town stands upon a protrusion of serpentine ; and on either 

 side extend masses of IIip})urite-limestone and associated schists and 

 shales, rising into elevated ridges 2000 and 3000 feet high. 



In the broad valleys and bays formed by the curvature of these 

 ridges and mountains are everywhere to be found one or other of 

 the two groups of tertiary deposits which are so well developed at 

 Oropo and in the hills north of it *. 



The first of these basins to the north of Chalcis is the Steni Valley, 

 lying at the foot of Mount Delphi, but open to the sea at Politika. 

 This is about eight miles square, and seemed to be composed of both 

 of the freshwater groups ; the beds lying nearly horizontal. They 

 were identified as being of freshwater origin in crossing this basin, 

 on a journey from Chalcis to Mount Delphi ; and a few fossils were 

 procured, including a rather large-sized Ampidlaria, near the vil- 

 lage of Gides, at about 700 feet above the sea. But the examina- 

 tion was too hasty to enable me to give sections or details. The 

 overlying red sands and gravels did not appear to be more than 50 

 or GO feet thick at any place where met with ; and they were often 

 wanting. 



At the foot of the mountains, rising from the margin of the valley 

 under Steni, a serpentine protrudes beneath disturbed and altered 

 schists and limestones, which dip to the N.E. at angles from 50° 

 to 70°. 



The next group of deposits of freshwater origin forms the entire 

 promontory of Melasina in the Eparkeia of Atalanta on the Locrian 

 coast. This is almost wholly composed of white compact strata of 

 the lower lacustrine series ; but it is capped by some fragments of 

 red marls, gravels, and sands, which seem to be of subsequent date 

 to either freshwater group, unless they form an upper fragment of 

 the latter. The thickness of these deposits is nearly 1000 feet. 

 Masses of the Ilippurite-limestone, however, rise through them, and 

 were no doubt islets or rocks in the fincient lake. This Melasina 

 group dips to the S.E. at an angle of about 10°. 



The Atalanta valley or basin is composed of low ridges of red- 

 dish marls, sands, and gravel ; these, being soft and subject to rapid 

 waste, are channeled into deep ravines, in which the deposits are 

 well exposed, and exhibit a great abundance of fossils. By means 

 of the fossils this softer group is clearly identified as of freshwater 

 origin ; and aj)j)arently it was contemporary with the newer fresh- 

 water deposits before described as occurring in the southern division 

 of the Archipelago, viz. Xanthus f, Rhodes J, Kos, and Cerigo ; and 

 I may say, from my more recent discoveries, in Crete also, where 

 similar freshwater deposits exist at several localities. 



The Atalanta deposits are most fossiliferous near the village of 



* See Map, pi. 4, Quart. Journ. Geol. Soc. vol. iii. 



t Travels in Lycia, vol. ii. p. 164, &c. ; Quart. Journ. Geol. Soc. vol. ii, p. 10. 



X Proceed. Geol. Soc. vol. iii. p. 774. 



