580 Annals ok the Carnegie Museum. 



naria, but generally the columns are so obscure and broken that it is diffi- 

 cult to determine the nature of the fossil. 



"The mass is not uniformly of the character described. At Essex the 

 beds are more regular, and presents externally a better aspect, and forms in 

 consequence a better building stone. As a limestone, it is purer than the 

 calciferous. 



" The position of the Chazy limestone is clearly detmed at Chazy, lying 

 between the calciferous and birdseye limestone. 



"There are three well-marked fossils which make their appearance in 

 this rock ; the Afaclur-ea, a Trochtts and a Columnaria. Beside these, 

 there are numerous small fossils, which the irregular bedding of the rock 

 conceals. 



"The entire thickness of this rock is not far from 130 feet. It is de- 

 veloped at numerous localities along Lake Champlain, particularly at Essex, 

 and at Chazy in Clinton County." 



In a footnote referring to Macliirea, Professor Emmons says: "This 

 fossil was first described by C. A. Le Sueur under the generic name Mac- 

 lurites, in honor of William McClure. As the termination of this name is 

 evidently erroneous, I propose to change it as above, in order to preserve 

 the commemoration intended to a most munificent patron of science." 



On succeeding pages he describes the occurrence of the Chazy at Crown 

 Point and Essex, and gives a good figure of Macluiitcs mai^ttits. On page 

 315 the strata at Chazy are described. The lower part of the section is 

 assigned to the calciferous sand rock and the upper part included in the 

 Birdseye limestone, thus leaving only the middle portion as the original 

 Chazy. The fossils of the Chazy formation at Chazy are : "The Madiirea 

 is most abundant. ... A much smaller species is common at Chazy, in 

 which the thickness is the greater portion of the disk. ... In the mass 

 above the oulite, numerous orbiculre ^^ appear. These are quite deep, or 

 rather conical, and we find only the convex valve." 



I 845. Adams, C. B. First Annual Report of the State Geologist of Vermont, p. 44. 



In describing the economic products of Isle La Motte, the author s])eaks 

 briefly of some quarries in the Chazy. 



" At Hill's quarry, on the east side, Machirea is often found, and speci- 

 mens sometimes reach five inches in diameter. 



Cook's quarry, on southeast end of the island. Strike N. 65° E. dip 4° 

 or 5° to northwest. The beds show corals, encrinites, and Macluren. 



Fisk's quarry on southwest end of island. This is the most extensive 

 marble quarry in \'ermont and was wrought before the war of the Revolu- 

 tion. Strike, north and south. Dip 5° or 6° east. The rocks consist 

 chiefly of fragments of corals, with Machtrca in abundance, and a small 

 Orthoceras and other chambered shells. One Maclurea was seven inches in 

 diameter." 



ss* Evidently species of Archinace/Ia and Scetulla. 



