I860.] SPEATT BESSARABIA, ETC. 281 



stone, Culm, Grauwacke, Upper Carboniferous formation, and the 

 Permian formation (Murchison). 



Observe : — (a.) All these portions of the flora of the Lower Carbo- 

 niferous formation have a very great affinity with each other, and all 

 contain three remarkable species (Calamites transitionis, C. Hcemeri, 

 and Sagenaria Weltheimiana \_Knorria imbricata~\), which truly de- 

 serve to be called " Leitpflanzen " (characteristic plants). 



(b.) The genus Knorria, Sternb., ought no longer to exist. It is 

 only a form of the genus Sagenaria or Lepidodendron, and the most 

 common species, Knorria imbricata, belongs to Sagenaria WeltJieim- 

 iana. 



(c.) Stigmaria ficoides is in reality a rhizoma of Sigillaria. I 

 possess a great number of different degrees of development of this 

 remarkable plant, which ought to be figured and published, but at 

 present I do not know whence they have come. 



Some time ago I had the honour of sending you a memoir en- 

 titled " Die angeblich in der Grauwacke vorhandenen Kohlenlager," 

 &c. (" The Coal-deposits supposed to exist in the Grauwacke "), in 

 which I announced the locality whence I had obtained specimens of 

 Pterygotus Anglicus with the Graptolites, the first found in Germany. 



I have to request that you will have the kindness to communicate 

 all these observations to the Geological Society, of which I have the 

 honour to be a Foreign Member. 



2. On the Freshwater Deposits of Bessarabia, Moldavia, Wal- 

 LAcniA, and Bulgaria. By Captain T. Spratt, R.N., C.B., F.H.S., 

 F.G.S. 



In some brief papers recently published in the Society's Journal*, 

 I have drawn the attention of geologists to the freshwater deposits 

 which so extensively form the margin of the Grecian Archipelago 

 and the Sea of Marmora. 



I have also stated, that they seem to mo to be connected with 

 similar freshwater deposits which I have described as existing in the 

 southern part of the Dobrutehaf, between ikdjik and Kustenjeli ; 

 and with others bordering different parts of the Black Sea. such as 

 those noticed bj Hamilton in the valley of the Ealya nearSinope; 

 and by Pallas, De Hell, and others at Kertch, Taganrok, and Odessa. 

 All these give fragmentary indications of a great Oriental Lake hai ing 



extended over the area of the (ireeian Arehipelago, the Black Sea, 

 and Sea of Azof. 

 From recenl observations made whilst employed within the Delta 



of the Danube and the adjacent lakes, I am enabled to state that 

 large portions of the southern parts of Bessarabia, Moldavia, and 



* Quart. .lourn. Gfeol Soft vol. \iv. p. 212. 

 t Ibid. vol. xiii. p. 77 ; Hid vol. xiv. ]>. 208 



