Otology and Mineralogy, 237 



i 



A typical section .from which the above measurements were 

 taken is found in Eastern Shoreham, Addison County, Yt. In 



this section not only are all the strata of the Calciferous seen, hut 

 the whole Lower Silurian appeal's from Potsdam to I'tica Slate 

 in a Continuous series. This locality was first pointed out by 

 Rev. Augustus Wing, and denominated the " Bascom Ledge. 

 [This Journal, 1S77, vol. xiii, p. 343.] 



The paleontology of the Calciferous is not complete, though 

 good advance lias been made. Division A has not yielded dis- 

 tinguishable fossils. Division B seems to he the horizon of the 

 original Orthoceras primigenium ofVanuxem. It contains also 

 the remarkable banded masses which at, one time were regarded 

 concretions ami were figured and described as such by Dr. J. 

 II. Steel. [This Journal, J une, 1825, vol. ix, pp. 16-19.] Mather, 

 in his X. Y. Report, recognizes their organic origin. Probably 

 the fossil is a Cryptozoou and the form may be known as Crypto- 

 zoon Steeli. 



Division C, besides containing the numerous worm burrows at 

 its base, Scollthus minutus, according to Wing, holds some 

 poorly preserved forms of gasteropds and cephalopods. 



Division D is rich in fossils. Sponges, brachiopods, gastero- 

 pods, cephalopods, trilobites and ostracods appear. The abun- 

 dant fauna of the Fort Cassin rocks belongs here. Thirty-five 

 genera have been gathered. 



Division E, though apparently not so fossiliferous as D, adds 

 new forms, generic as well as specific, and brings the number of 

 Calciferous genera above forty with species numbering from one 

 to ten. 



Besides the section referred to at Eastern Shoreham, other 

 exposures have been investigated. One section from the vicinity 

 of Ticonderoga takes in Mt. Independence, Lake Champlain, and 

 the grounds of the old Fort. The rocks at Orwell, Fort Oassin, 

 Charlotte, Providence Island, and Phillipsburgh, Canada, expose 

 a part or the whole of the divisions of the Calciferous. 



The series of rocks at Phillipsburgh extend from four to five 

 miles into Vermont. Logan's division A with its three subdi- 

 visions, seven hundred leet in thickness [Geol. Canada, p. 844], 

 is lithologically identical with the divisions A, B, and C, respec- 

 tively of the Calciferous. The fossil Cryptozopn Steeli [n. sp.] is 

 seen in the reticulated limestone of A 2, at Phillipsburgh. Simi- 

 larly the first four of Logan's division B correspond to the later 

 division D of the Calciferous both in lithological character and 

 in fossils. (Geol. Canada, pp. 278, 279.) The beds of the Calcif- 

 erous sandstone are as peculiar at Phillipsburgh as at Shoreham. 



A similar comparison might be made between the Calciferous 

 of Lake Champlain and the 1830 feet of strata on the northwest 

 coast of Newfoundland, (Divisions D to L of Geol. Canada, p. 

 £65, et seq.). 



Misapprehensions in regard to some of the rocks of Vermont 

 are to be corrected. Certain slates referred to the Calciferous 



