1819.] Geological Society. 141 



A paper was read from the Hon. W. I. H. I. Strangways, on 

 the strata in the brook Pulcova, near the village of Great Pulcova. 



The Pulcova is a small stream which passes with a number of 

 angular sweeps through a deep ravine, the sides of which exhibit 

 a very singular disposition of their strata, which it is the object 

 of this paper to describe. 



In the upper part of the valley, we find only blue clay covered 

 by the alluvium ; as we descend, we meet with limestone lying 

 conformably above the clay, and afterwards portions of a green 

 or dark coloured clay, which rise up between the blue clay and 

 the limestone, the strata being much contorted, and dipping in 

 various directions. The green clay is interstratified with thin 

 seams of a whitish sand, so as to produce a striped appearance 

 in its sections. In some parts these alternations of green and 

 white sand rise up like the summit of a rounded hillock ; in other 

 parts they are perpendicular, and occasionally they are twisted 

 in the most irregular manner. The beds of limestone also vary 

 much in their direction ; sometimes they are nearly perpendi- 

 cular ; they dip in opposite directions in different parts, and they 

 suffer various contortions. For a considerable space the three 

 strata, during all their contortions, are conformable to each 

 other ; but we afterwards arrive at a spot where the limestone is 

 but slightly inclined, and seems to abut abruptly against the beds 

 of clay, which are here nearly vertical. The position of the 

 limestone in relation to that of the green clay is, however, ren- 

 dered somewhat doubtful, in consequence of the tendency which 

 the former rock has to divide itself into cubical fragments, which 

 renders the actual direction of the strata somewhat uncertain. 

 Some portions of the limestone consist of a number of strata, 

 which are variously coloured ; and in consequence of its 

 tendency to divide into cubical fragments in certain parts 

 presents the appearance of a beautiful tesselated pavement. The 

 paper was accompanied by a map, and a number of illustrative 

 drawings. 



An abstract of a letter from Dr. Nugent, of Antigua, to the 

 President, was read, accompanying some specimens of the 

 Barbuda limestone, and containing some remarks on the geology 

 of that island, and of Antigua. 



Dr. Nugent describes Barbuda as consisting of a hard, level, 

 limestone, with scarcely any vegetable mould upon it, a good 

 deal of brush wood and copse growing in the crevices, and 

 being altogether about 20 miles long, and 13 or 14 broad. The 

 limestone is supposed to be of the same formation with that of 

 Antigua. The fossils in the Barbuda rock at first view appear 

 to be recent, but this idea is inconsistent with the connexion 

 between the Barbuda limestone and that of Antigua in which so 

 many siliceous fossils occur. 



The author remarks that the more mountainous parts of 

 Antigua consist of trap rocks, on which rests a series of strati- 



