PALEONTOLOGY :. EASTERN MASSACHUSETTS. 47 



growth. " The crab Archccoplax signifera is mainly found in the 

 lower portion of this stratum ..." (Wood worth). 



The Miocene is nowhere more than ten feet thick ; and usually, 

 by reason of erosion, it is much less. It rests unconformably on 

 the Cretacic, the Eocene being absent. 



Pliocene. From a series of fossils collected by Woodworth from 

 the sands overlying the Greensand beds, Dall identified the fol- 

 lowing species : 



Venericardia borealis Conr. 

 Astarte castanea Say. 

 Spirula polynyma Stm. 

 Corbicula densata Conr. 

 Macoma lyellii Dall ? 

 Nucula shaleri Dall var. ? 

 Purpura lapillus L. 



Dall holds that " on the whole these specimens indicate a more 

 recent fauna than the Miocene . . . and may perhaps be regarded 

 as representing the Pliocene." 1 



2. INDIAN HILL. 



(Cretacic.) 



Professor Shaler has described fossiliferous Cretacic rocks from 

 the north shore of Martha's Vineyard. 2 The locality is nearly south 

 of Indian hill, in immediate proximity to the Martha's Vineyard 

 esker, and a few hundred feet east of a ruined building known 

 as Wood's schoolhouse. " The schoolhouse of the name has 

 disappeared, for its foundations only remain ; but the explorer 

 can readily find his way to the spot by passing from the new 

 schoolhouse on the Cedar Tree Neck road westwardly along the 

 serpent kame, the only deposit of this nature on the island, until 

 he passes a stone wall, a little to the west of which, in the road- 

 way and on the bare ground thereabout, he may find an abun- 

 dance of fragments of this peculiar sandstone." 3 The sandstone 

 is of a reddish color, coarse, and abounds in quartz pebbles, and 

 the fragments are angular. They are mingled with the till, and 



i Dall, loc. cit., p. 300. 



2 X. S. Shaler. Cretaceous fossils on Martha's Vineyard. Mus. Comp. Zob'l., Bull., 

 vol. 16, no. 5. 



sShaler, loc. cit., p. 90. 



