Vol. 60.] THE DISTRICT SURROUNDING THE DARDANELLES. 29! 



EXPLANATION OF PLATE XXIV. 



[All the figures are drawn of the natural size, except where otherwise stated. 

 The specimens are preserved in the British Museum (Natural History).] 



Didacna crassa, Eichwald. (See p. 280.) 

 Pliocene (Sicilian): Baschesrne Bay, Gallipoli. 



Fig. 1. External view of right valve. 



2. View showing urabonal summit and dentition of the same valve. 



[L. 13661.] 



Dreisscnsia polymorpha, Pallas. (See p. 280.) 

 Pliocene (Sicilian) : Gallipoli. 



3. External aspect of a left valve — the specimen is attached to a con- 



glomeratic matrix filling the interior of a valve of Didacna crassa. 

 [L. 13661.] 



Drcissensia Tschaudce, Andrussov. (See p. 280.) 

 Pliocene (Sicilian) : Gallipoli. 



4. Outer view of a right valve. [L. 13662.] 



Lyrccea Bonelli (Sismonda), Brusina. (See p. 281.) 



Miocene (Pontian) : from above the Xuminulitic Limestone 



at a brook north of Teke-keui. 



5. Front aspect, showing aperture. 



6. Dorsal view of the same shell. 



Drcissensia riraesticnsis, Fontannes. (See p. 281.) 



Miocene (Pontian) : from above the Xummulitic Limestone 

 at a brook north of Teke-keui. 



7. External view of a right valve. 



8. Inner view of a left valve, belonging to another specimen. x2. 



Prosodacna cf. stenopleura, S. Stefanescu. (See p. 281.) 



Miocene (Pontian) : from above the Xummulitic Limestone 



at a brook north of Teke-keui. 



9. Interior of a right valve. 



10. External view of the same specimen. 



Melania cf. Escheri, Merian. (See p. 283.) 

 Miocene (Sarmatian) : Potamina Dere. 



11. Fragmentary specimen, exhibiting sculpture-characters closely 



resembling this species. 



Melancypsis incerta. Ferussac. (See p. 283.) 

 Miocene (Sarmatian) : Potamina Dere. 



12. Apertural view. 



13. Dorsal view of the same specimen. 



Unio Delcsserfi, Bourguignat. (See p. 283.) 

 Miocene (Sarmatian) : Potamina Dere. 



14. External view of a right valve. 



This determination is according to D'Archiac's interpretation of 

 Bourguignat's species from Palestine: see Viquesnel's 'Voyage [dans 

 la Turquie d'Europe ' vol. ii (1868) p. 479 & Atlas, pi. xxiv, fig. 1 a. 



Melanopsis costata, Olivier. (See p. 284.) 



Miocene (Sarmatian) : found beneath the Mactra- 



Limestone at San Stefano. 



15. Front view of a specimen showing the characteristic sculpture of this 



species. 



