2 GEOLOGICAL MEMOIRS. 



The author gires the follomng hst of MoUusca found in the tertiaiy 

 marine formations of Andalusia : — 



Sti'ombus gallus. Cardita squamosa. 



Ranella gigantea. Lucina iucrassata. 



Pleurotoma colon. Pecten nodosus. 



TuiTitella subaiigulata. burdigalensis. 



colon. Ostrea callifera. 



Calyptraea trochiformis. Balanus tintinnabulum. 



Natica lyrena. PoUicipes ? 



Dentalium Boueii. Caryophylla indeterminata, 



hexagonalis. Clypeaster altus. 



striatus. Kleinii. 



Corbula revoluta. 



and adds that this hst might be greatly augmented, if there were only- 

 one person in Andalusia who took an interest in this branch of Natural 

 History. 



The second volume contains a paper on the tertiary formations in 

 the neighbourhood of Burgos, by Don Felipe Naranjo y Garza ; from 

 which I have extracted the folloT^ing remarks : — 



The country to the north of Burgos between the rivers Arlanzon 

 and Ubierna, consists of the following strata in ascending order : — 



1 . Hoiizontal beds of reddish plastic clay alternating with fine and 

 disintegrating arenaceous beds of a brown-grey colour, from fom- to 

 six inches thick each. 



2. Beds of gypsum half a foot thick, alternating with grey marls 

 eight to ten inches thick each : and 



3. Calcareous beds of greater or less thickness equally horizontal, 

 occupyuig the upper part of the deposit and crowning the summits of 

 the neighbouring hills. 



The varying extent to which these formations have been worn down 

 and denuded has given to the country generally an undulating cha- 

 racter mtersected by ridges of greater elevation. 



The first or lowest of these formations does not contain any organic 

 remains. It is seen near the fountain of Buenavista, not far from the 

 town of Burgos. The second may be observed in the neighbourhood 

 of Villatoro, where compact gypsum or alabaster is abundant, accom- 

 panied by selenite and sometimes fibrous gypsum. The third is es- 

 sentially calcareous, and is seen on the summits of the hills in the 

 neighbourhood of the Monasterio de Gerdnimos de Fres del Val. It 

 contains many remains of 



Planorbis carinatus. Limnaeus longiscatus. 



Limnaeus stagnalis. 



The author considers the above evidence sufiicient to prove that 

 these beds belong to the plastic clay gypseous marls, and siliceous 

 freshwater limestone, and consequently to the most recent tertiary- 

 formation. The fossil remains prove that the basin was at a recent 

 geological period covered by a freshwater lake, in which the above- 

 mentioned beds were tranquilly deposited. 



The lowest of the three groups was only visible in a few localities ; 

 the author had consequently no opportunity of ascertaining whether 

 it contained the remams of mammiferous animals. Proceeding to the 



