Vol. 60.] THE DISTRICT SURROUNDING THE DARDANELLES. 287 



species from those figured by A. d'Archiac in Viquesnel's work l as 

 M. incerta, Ferussac, var. Melanopsis fusiformis is characteristic 

 of the Headon Beds of England. 



Locality. — Keshan Colliery, associated with Corbula and in- 

 determinable plant-remains. 



Horizon. — Oligocene (Stampian) greenish marls. 



Mollusc a — L amellibr anchi a . 

 Corbicula semistriata, Deshayes. (PI. XXIV, figs. 21-23.) 



Cytherea (?) convexa, Brongniart, in Cuvier's 'Recherches sur les Ossemens 



Fossiles ' 2nd ed. vol. ii (1822) pt. ii, pp. 282, 284, 458, 462, 612 & pi. viii. 



figs. 7 a-1 b (insufficiently denned for adoption). 

 Cyrena semistriata, Deshaj'es, 'Encycl. Method.' vol.ii (1830) pt. ii, p. 52. 

 Cyrena subarata, Bronn, ' Lethsea Geognostica ' 2nd ed. vol. ii (1838) p. 958 & 



pi. xxxviii, fig. 2. 

 Cyrena semistriata, J. Morris, in Edw. Forbes's ' Tert. Fluv. Marine Formations 



of the Isle of Wight ' Mem. Geol. Surv. (1856) p. 148 & pi. iii, fig. 2. 



The specimens representing this species exhibit the variations of 

 contour referred to by John Morris in 1856. Some of the valves 

 are more equilateral, others being more obliquely produced on the 

 posterior side ; the dentition is solid, strong, and prominent, and 

 the concentric sulcate structure is rather more pronounced on the 

 anterior than on the posterior side of the shell. 



This is a very characteristic species of the Oligocene Period, having 

 been collected in England and in many Continental countries, such 

 as France, Germany, Hungary, Galicia, etc. At Fontainebleau, 

 nearly 40 miles south-east of Paris, it is abundantly found in beds 

 which Prof. A. de Lapparent and others recognize as Middle 

 Oligocene, or the so-called Stampian part of that system. Vacek * 

 records its occurrence in the Menilit-Schiefer ( = Stampian of A. de 

 Lapparent) near Also-Vereczke, on the confines of Galicia, in 

 association with Meletta sardinites, and considers that the beds 

 should be synchronized with the Lower Oligocene of Schilag, in 

 Transylvania, as described by Dr. K. Hofmann. 3 Hebert & 

 Munier-Ch almas 4 recognized the shell in the Hungarian lignites 

 of Gran, and Dr. E. Ponrnier 5 records it from the Central Caucasus. 

 Lastly, it is well represented in the Hempstead Beds of England. 

 As a fossil from the region of the Dardanelles, it is now known for 

 the first time. 



Horizon. — Oligocene (Stampian). 



Localities. — Masatly; Harmanly ; north-west of Keshan ; and 

 3 miles inland from Hora. 



Corbtjla sp. 



A small trigonal form of Corbula makes up very largely the green 

 marly rock found at Keshan. The specimens are difficult to diagnose, 



1 ' Voyage dans la Turquie d'Europe ' vol. ii (1868) pi. xxiv b, figs. 4 & 5. 



2 Jahrb. d. k.-k. geol. Eeichsanst. vol. xxxi (1881) pp. 200-202. 



3 Verbandl. d. k.-k. Geol. Reichsaust. 1881, p. 16. 



4 C. R. Acad. Sci. Paris, vol. lxxxv (1877) p. 184. 



5 These presentee a la Faculte des Sciences de Paris : ' Descr. Geol. Caucase 

 Central' (Marseille, 1896) pp. 184, 186. 



