360 P. E. Raymond — Fauna of the Chazy Limestone. 



Division 3. — This is especially well developed on Valcour 

 Island. Zone 3 a is exposed in two or three localities on the 

 east side. Zone S b is best developed about Cystid Point, the 

 southeast point of Valcour Island, and zone 3 C is exposed both 

 east and west of Black River Point on the north end. The 

 division is 172 feet in thickness and carries Camarotwchia 

 plena throughout. The faunules given for zones 3 a , 3 6 , and 

 3 C , are those found on Valcour Island. 



Crown Point Section* 



The section at Crown Point is 305 feet in thickness. At the 

 base is a zone 25 feet thick in which the strata are sandstone 

 and shale, and the only fossil is Lingula ovainerdi. The 

 remaining 280 feet are impure blue and grey limestone, usually 

 very fossiliferous. Division 1 is absent. 



Division 2. — The fauna characteristic of this division is 

 found all through the section at Crown Point. The character- 

 istic fossils — Maclurites magna, Rajinesg'idna cha??iplainensis, 

 Plmsiomys platys, and Peperditia limatula — are very abun- 

 dant, and the whole expression of the fauna is that of the mid- 

 dle part of the section at Valcour Island and elsewhere. 

 Brainerd and Seely assign the lower 48 feet to their Division 

 A, and the upper 57 feet to Division C, but faunally the whole 

 section belongs together. Camarotozchia plena is absent, as 

 are also the other fossils characteristic of Division 3. The 

 upper 3 feet of the section are a coarse limy sandstone, with 

 Plwsiomys platys, Camarella varians, Raphistoma stamin- 

 eum, and Isotelus harrisi in a layer a foot thick at the top. 



One ell, Vermont. 



A short distance northeast of Orwell village is the most 

 southern exposure of the Chazy. At that place there are 

 about 60 feet of strata, the fauna of which indicates that they 

 belong to Division 2. Another locality near by shows sand- 

 stone and shale at the base of the formation. 



North of the International Boundary the various divisions 

 can not be followed in the published lists, but this is due to tHe 

 fact that no sections have been made in that region. The lists 

 published by Billings, Logan, and Ami, of the Canadian Sur- 

 vey, however, do show that fossils characteristic of all three 

 divisions are found in that region. The Champlain Valley 

 fauna of the Chazy, which will be designated as the typical one, is 

 found as far north as Joliette, 35 miles north of Montreal and 



* For detailed description of this section, see Bull. Amer. Pal., vol. iii, 

 No. 14, 1902. 



