208 TRANSACTIONS OF THE [1892 



obtained from the south side, and resting in undisturbed 

 beds, were found in fairly good condition, with enough of 

 their outline and venation to establish their agreement 

 with the forms above cited ; while those collected from the 

 west side exposures, being included in a shattered and less 

 coherent matrix, were almost too friable to be touched. 



The section on the south-west face of the cliff is covered 

 from top to bottom by the white sand, which has been 

 washed from above. Its beds are all in place, nearly hori- 

 zontal, and form a very steep exposure (apparently of about 

 70°), abutting against the high ridge of variegated, partly 

 red, clay on its south-eastern flauk, and likewise resting 

 upon the base-levelled surface of the same body of clay. 

 On the west face of the cliffs, this same group of alternat- 

 ing beds forms three widely separated buttresses upheld 

 in nearly original order. The erosion of their sides has 

 cut them into almost vertical crests, projecting from the 

 body of the ridge ; while the intervening material has been 

 trenched by heavy rains, and perhaps melting snow, and 

 partly carried away by the surf of Yineyard Sound. The 

 base and lower parts of all of these is covered and dis- 

 guised by material washed or dropped from the upper 

 beds; but they all rest upon the degraded surface of the 

 variegated clay.* 



The best preserved section, that of the south-west face of 

 the cliff is composed as follows, in descending order : — 



Ten to fifteen feet of coarse, kaolinic white sand, gray 

 within, composed of disintegrated granitic rock. 



Three to five feet of fine plastic drab clay, massive in part. 



Twelve to fifteen feet of the alternating block and 

 lead-colored lignitic, partly laminated, clay in narrow 

 layers, parted by thin seams of fine white sand. Highly 

 fossiliferous. 



* Since preparing the first part of this paper my attention has been called to the 

 fact that my friend, Mr. David White, was the first to place on recoi-d the discovery 

 of veritable Cretaceous fossil plants at Gay Head and other places in Martha's 

 Vineyard. See American Journal of Science, 1890, vol. 39, pages 93-. 



