1>. WhiU — Cretaceous Plants from Martha's Vineyard. 95 



The report nf the Stare geologist, published in L832,* contains 

 a map on which this region is colored and described as Tertiary. 



hi the Report published in L833,f which was accompanied by 



1 map and atlas, the organic remains are discussed ami figured, 

 and a short description of the Gay Head cliffs is given. The 



same material, so far as it concerns Martha's vineyard, is 

 repeated in the " Final Report," of 18il,J with a more extended 

 stratigraphica] description, and a section of the cl ill's. This is 

 the most important contribution to the subject that appeared 

 prior to Professor Shaler's work in 1889. From the similarity 

 of the lithologic characters, and the evidence of the organic 

 remains, the conclusion is reiterated and confirmed that the 

 clays are Eocene, and equivalent to those of Europe. Dr. 

 Hitchcock regarded many of the fossils, especially the bones, 

 as having been rolled and broken, probably from re-deposition. 

 A description of the strata, mammals, fishes, Crustacea and 

 mollusca was given in 18-11 by Lyell,§ who saw no indications 

 of the occurrence of Cretaceous strata in any fossils appearing 

 to have been washed out from the Cretaceous to form the clays, 

 which were judged by him to be Miocene. Save Professor 

 H. D. Rogers' assent] to Sir Charles' conclusions, and Desor 

 and Cabot's correlation of the clay at the base of Sankoty Head 

 in Nantucket with those of Gay Head, which they regarded as 

 representing the opposite side of a Miocene basing there seems 

 to have- been no further discussion of the subject till 1860, 

 when Dr. William Stimpson announced the discovery, without 

 giving descriptions, of new fossils, bones, mollusca, etc., which 

 persuaded him that the strata were Cretaceous, rather than 

 Eocene.*"* Three years laterff he added a description of Archce- 

 oplax signifera, a new T genus and species of fossil crab, wdrich, 



* Edward Hitchcock: Report on the Geology of Massachusetts; examined . . . 

 duriog . . 1830 aud 1831, this Journal, vol. xxii, 1832, pp. 1-70. The same was 

 published that year as the regular Report of the Survey, " pt. ), Economic," and 

 comprises pt. 1 of the Report for 1833. 



f Report on the Geology, Mineralogy, Botany and Zoology of Massachusetts, 

 etc., 1833, with map and atlas. (See pp. 172-204, pi. xi.) 



% Final Report on the Geology of Massachusetts, vol. h, 1841. (See pp. 422- 

 434, pi. xix, liv.) The clays are mentioned in nearly every report which touches 

 upon the economic geology of the State ; only those in which their age is consid- 

 ered are here included. 



£ Sir Charles Lyell : On the Tertiary Strata of the Island of Martha's Vineyard 

 in Massachusetts, Proc. Geol. Soc. London, vol. iv, No. 92 ; this Journal, vol. xlvi, 

 1844, pp. 318-320. 



I H. D. Rogers: Address before the American Assoc. Geol. and Nat., May, 

 1844, 1. c. vol. xlvii, 1844, pp. 247-278. 



^[ E. Desor and E. C. Cabot: On the Tertiary and more recent Deposits in the 

 Island of Nantucket. Quart. Jour. Geol. Soc, Loudon, vol. v, 1849, pp. 340-344, 



2 figs. 



** William Stimpson : Cretaceous Strata at Gay Head, this Journal, II, vol. 

 xxix, 1860, p. 145. 



ff On the Fossil Crab of Gay Head, Boston Jour. Nat. Hist., vol. vii, 1 863, pp. 

 583-589, pi. xii. 



