Geological Society. 151 



The whole area of the basin, with the exception of an insulated 

 group of transition limestone rocks near Granada, is occupied by con- 

 glomerates, marl, gypsum, and limestones containing freshwater 

 shells. The conglomerates predominate to the north and east of 

 Granada, and form a high tract of waving hilly ground between that 

 city and the eastern part of the Sierra Nevada j and the other depo- 

 sits prevail through the southern portion of the basin. The valley 

 through which the Genii flows is the lowest part of the district, and 

 is composed near Granada of a disintegrated conglomerate. 



The author gives a detailed account of the geological appearances 

 presented along the line of road from Granada to Alhama. The lower 

 strata consist of beds of gypsum alternating with strata of marl and 

 marly, micaceous sandstone. The gypsum is in general of the ordinary, 

 fibrous variety j but near the village of Escuzar, alabaster of a beau- 

 tiful whiteness is quarried. In the bed of a rivulet passing by La Mala 

 a brine-spring issues, which yields from 18,000 to 24,000 fanegas of 

 salt yearly ; the fanega being equal to 251bs Spanish. The strata of 

 marl and gypsum are covered with a compact limestone, containing 

 casts of Paludinse ; and on this limestone rest irregular masses com- 

 posed almost entirely of comminuted shells of the genera Limnsea and 

 Planorbis. The fossils found in these limestones have been examined 

 by Mr. J. Sowerby, who has supplied the following list: — 

 Planorbis rotundatus, found in the Paludina pusilla, of Deshayes. 



Isle of Wight. Paludina Desmarestii. 



Planorbis rotundatus vel planu- Paludina pyramidalis. 



latus. Ancylus. 



Planorbis, new species. Cypris. 



Bulimus pusillus, of Broard. Limnaa. 



The structure of the country around Alhama is explained by three 

 sections in the immediate vicinity of that village. One of these, ob- 

 served by following the horse-road from Alhama towards Loja, presents 

 in an ascending order the following succession of horizontal strata, 

 and may be taken as the type of the others. 



1. The nummulite limestone, which constitutes the boundary of part 

 of the basin. 



2. A coralline limestone, which in some parts alternates with a 

 calcareous sandstone and a fine-grained conglomerate ; the sandstone 

 abounds with a Pecten, which resembles the Pecten reconditus of the 

 London clay. 



3. The rock composed of alternate strata of gypsum and marl. 



4. The freshwater limestone with Paludina, above described, which 

 forms a table land, extending in the direction of Loja as far as the eye 

 can reach. 



Under the freshwater limestone, near the village of Arenas, is a 

 large deposit of brown coal of unknown depth. The remains of Pla- 

 norbis are abundant in the upper layers of it. 



In conclusion, the author states that he had observed a compact 

 limestone containing Limnsea and Planorbis, near Partaloba, in the 

 province of Granada ; Montesa, in the province of Valencia and La 

 Gineta ; and Ocana, in the province of La Mancha ; — that he had like- 



