114 FOSSIL ESTHERIiE. 



associated with lava and scoriae, and granite rich in garnet, yellow topaz, and aqua-marine. 

 Mr. Austin thinks that the shale-beds formed the surface at the time of the last igneous 

 eraption of any magnitude in that part of Siberia, and that it was then disturbed and 

 covered by the volcanic products. He noticed in the shale, besides the Eishes and Crasta- 

 ceans, one spiral shell {Limncea or Paludina F), several impressions of stems and reed-like 

 plants, and a small rhomboidal piece of Hgnite; but nothing more definite can be 

 at present said of the age of the deposit than that it is probably of Tertiary age, and of 

 freshwater origin. 



Mr. W. Davies, of the British Museum, informs me that Aspius (such as accompanies 

 Estheria Middendorfii, see above, p. 112) was a true freshwater fish, of the Cyprinoid 

 family, and closely related to Leuciscus, differing from the latter genus in having a more 

 compressed body, and a more slender skeleton. The species are found in Miocene 

 Tertiaries, as the freshwater limestone of (Eningen and the lignites of Menat, &c. 



Note. — Althougli the Purbeck specimens hitherto supposed to be Estherian are Archseoniscal (see 

 p. 105), yet there are real Purbeck EsthericB ; for Mr. Harry Seeley, F.G.S., of the Woodwardian Museum, 

 Cambridge, informs me to-day that an Estheria, "very like the Hastings species, has just been detected in 

 the Lowest Purbeck beds near Swanage." — December 17, 1862. 



