SWAN PRINCES ISLANDS. 59 



designated the " Coral-reefs " of the Devonian system of Turkey. 

 Some beds, in particular, seem to be entirely composed of a mass 

 of ancient coral. The full dip of the strata is nearly south-west, 

 at an angle varying from 35° to 70° ; and a very regular ascending 

 series can be traced from the northern to the southern extremity of 

 the island. 



Beginning at the northern end, the strata are composed of yellow, 

 brown, purple, and grey (the latter predominating) hard shales, 

 with grey and brown bands of impure limestone, and dipping regu- 

 larly S. 40° W. to S. 55° ^Y., at an angle of from 35° to 40°. 

 These beds are rich in fossils of various Idnds. Here are Corals of the 

 genera Heliolites — H. porosa (Porites pyriformis) &c. ; of Favosites, 

 F. polymoiplia, F. Gothlmidica, F. Goldfussi, &c. ; of Cup-corals, 

 Ci/athopJiyllum ccespitosum, C, vesiculosum, &c., and many other 

 beautiful varieties similar to Zaphrentis, Strepliodes, Ompliyma, 

 iStrombodes, &c. To these may be added many forms of the genera 

 Fenestella, Syrinfiopora, and Aidopora serpens, the two latter very 

 characteristic. Highly characteristic, also, of these beds are the 

 Brachiopod shells Atrypa reticidaris and A. squamosa, or A. aspera, 

 and the univalve Euomplialus, both large and small species, besides 

 several other Brachiopods in abundance, such as Leptcena, Stroplio- 

 mena, Atrypa, Spirifera, Orthis &c. ; also the Pteropod shell Ten- 

 tacidites annidatus, and stems of large Encrinites. Trilobites are 

 rare, one of the genus PTiacops, and an undescribed form, having 

 alone been met with in those beds ; neither have I been more suc- 

 cessful in detecting them in any other strata of the island. One thin 

 band of impure grey limestone near the north end is composed almost 

 entirely of large Spirifers, of species undescribed, one very similar 

 to S. concentrica of the Eifel beds in Germany ; while another band 

 of purple shale, a little further to the south, is laden with minute 

 Brachiopoda (Orthidoi &c.), with large EuompJiali, Corals, and 

 stems of small Encrinites. 



The next series of beds is composed of hard grey and purj^le 

 shales, much contorted, and dipping S. 5° E., from Qb° to 70°, in 

 which I could not discover any fossils. These beds are apparently 

 the same as those seen on the north-east side of Prinkipo, and in 

 which stems of Encrinites only could be traced. 



Proceeding south along the eastern side of the island, we now 

 arrive at thick beds of hard dark-grey subcrystalline limestone, dip- 

 ping S. 27° W., from 30° to 35°, stretching along the coast for a dis- 

 tance of about 150 yards, and replete with Corals of the genera Favo- 

 sites {F. Qothlandica), Heliolites {H. porosa), and another genus un- 

 described. Some of the beds are composed of a mass of Coral, while other 

 fossils are almost entirely wanting throughout their whole extent. 



Beyond them come in yellow and purple shales, and thick beds 

 of dark-grey limestone, contorted, dipping at their southern end 

 S. 30° W., at 75°, and containing many Corals and Brachiopoda. 

 In an old limestone-quarry near their termination, a trap dyke has 

 been exposed to view, of a light-green colour, and about 10 feet 

 wide, which crossed the island in a W.N.W. direction. 



