148 NEW YORK STATE MUSEUM 



I am informed by Doctors Lull and von Huene that recent study 

 of this fossil shows it to be the lower jaw of the pelycosaur and 

 hence indicative of Permian age.^ 



Volcanics. Air Richardson believed that the volcanic deposits, 

 on Amherst island particularly, lay at the base of the sedimentary 

 series. It may be quite true that the evidence of their transection 

 of the strata is obscure and even such obscure evidence may give 

 way to proof of interbedding. These volcanics are diabases which 

 stand out in nearly vertical posture on the sea cliffs, are highly 

 amygdaloidal, deeply weathered, and complicated with gypsum 

 deposits. In fact the compact beds are accompanied by agglomera- 

 tions of lava blocks, decomposed tuffs and gypseous clays in very 

 instructive association; wherever they lie in contact with the sand- 

 stones the latter are gray and hard, their induration and decoloration 

 extending for considerable distances away from the contact. The 

 apparent alteration of the augite or allied minerals in the diabase 

 to a chloritic condition gives it in many places a vivid green color 

 and its amygdules are found to contain analcite, chabazite, etc., 

 while the crevices and seams carry pyrite, specular hematite and 

 manganite. Sometimes the manganite is in considerable quantity 

 and excavations have been made for it on Grindstone, whence 

 nodules of comparatively large size have been taken. Frank D. 

 Adams made analysis of this manganite in 1881- and found it to 

 contain MnOo, 45-6i per cent ; water hygroscopic, o. 10 per cent. The 

 hematite also occurs in considerable rather impure masses. 



The association of the gypsum with the diabase is most intimate 

 and while the character of the former is discussed separately I shall 

 here refer to the mode of association. In the greater volcanic 

 exposures, as on Grindstone above Cape aux Meules and on the east 

 face of Alright, these vertical dikes make the highest cliffs. Here 

 the accompanying agglomerates of volcanic blocks, the great masses 

 of volcanic debris in the form of tuffs and ashes, have been referred 

 to. On Grindstone the volcanic masses (at least two distinct dikes 

 are present) have a thickness of fully a thousand feet; with them 



' Doctor Lull has given me the following citations relating to these remains : 



Leidy. On Bathygnathus borealis, an extinct saurian of the 

 New Red sandstone of Prince Edward's Island ; Journ. Acad. Nat. Sci. 

 Phila., (2), ii, p. 327-30, pi. XXXIIT, 1854. . 



Cope. Synopsis of the extinct Batrachia, Reptilia, and Aves of North 

 America, 1869, p. iig. 



Dana. Manual of Geolog>-. 4th ed.. 1896, p. 754, fig. 1180. 



Dawson, J. W. Acadian Geology, 1868, p. 119, fig. 29. 



Case. Revision of the Pelycosauria of North America. 1907, p. 63. 



von Huene. Neues Jahrb. f. Min., etc.. Beil.-Bd. 20. i8<)5. p. 343. 



' Chemical Contributions. Rept. Gcol. Survey Canada, 1881, p. 18. 



