BEENARDSTON SEEIES OF UPPER DEVONIAN. 259 



Professor Dana says (18, p. 381, note) that Professor Hitchcock's 

 "later conclusions have been influenced by his faith in the lithological test 

 of geological age and his unbelief in the existence of gneisslike metamor- 

 phic rocks of later date than the Cambrian;" which I can not think wliollv 

 just, since the latter, upon his atlas map, classes the wholly gueisslike band 

 ujjon the north line of the State and the quartzite, together with the stauro- 

 lite-schist — indeed, all the rocks in question except the hornblende-schist — 

 with the Coos group, and places this among the Paleozoic rocks in his final 

 scheme at the end of the Geology of New Hampshire, Vol. II. The dis- 

 crepancies are, however, sufficiently great between the interpretations of the 

 two authors, and I have placed in parallel columns their views and my own 

 of the ti'ue order of succession of the rocks in the area in question. See 

 also the section on page 285. 



1883. Mr. Whitfield (19) concludes, from an examination of the fos- 

 sils, that the limestones may be Middle Silurian; the shales (i. e., the 

 thin-bedded, rusty quartzite immediately above the limestone) were most 

 probably Middle Devonian. 



1890. The results reached by the writer were published in the Ameri- 

 can Journal of Science (20); but as several en-ors unfortunately escajied 

 his notice, the substance of the article is reproduced below in a con-ected 

 form. 



THE UPPER DEVONIAN AGE OF THE BERXARDSTOX FOSSILS. 



Prof. John Mason Clarke has been so kind as to reexamine the fossils, 

 and as he is familiar with the locality his conclusions may be considered as 

 setthng the age of the series with a large degree of probability. All the 

 fossils of the upper bed of shaly quartzite occm- also in the upper part of the 

 the limestone,and it is not possible to separate this continuous limestone mass. 



Professor Clarke writes me as follows (January 28, 1895) : 



The impressions left by the fossils are so distorted, obscure, and closely packed 

 together that a little imagination can construe them into species of all sorts of ages, 

 but I feel reasonably secure of the following jioints: 



First. The prevalence of a large spirifer, with moderately strong dental plates, 

 like S. granulosus Conr. of the Hamilt^jn group, or jS'. disjunctits Sow. of the Chemung. 



Second. The presence of Microdon, probably abundant among the distortion.s, 

 but recognized in a single instance. The species is uncertain, may be Hamilton, 

 Ithaca, or Chemung. 



