232 THE CAMBRTAN. [bull. 81. 



toma simplex, Murchisonia sp. !, and a Lamellibranchiate shell. The 

 fauna was correlated with that of the Potsdam sandstone of Iowa and 

 Wisconsin, although the rocks were referred to the Oalciferous forma- 

 tion. This reference was corrected in 1884. x 



In 1883, Mr. W. F. Ferrier called attention to the presence of tracks 

 on the Potsdam sandstone at the head of An Sable Chasm in Essex 

 County, New York. They were referred to the genus Gyrichnites of 

 Whiteaves. 2 Later the tracks discovered by Mr. Ferrier were made the 

 subject of a note by Sir J. W. Dawson, who proposed the generic name 

 of Clvdichuites for them. 3 



In a note on some obscure organisms in the roofing slates of Wash- 

 ington County, New York, Prof. James Hall redescribes Buthotrephis f 

 asteroides Fitch as Dactyloidites bulbosus.* 



A revision of the fauna occurring in the limestone beds of Saratoga 

 County was made by Mr. C. D. Walcott in 1886, and the following list 

 was published: 5 



NEW YORK. WISCONSIN. 



Cryptozoa proliferum 



Lingulepis acuminata Lingnlepis pinnseformis. 



Platyceras minutissimum Platyceras minutissininm. 



Platyceras hoy ti 



Metoptoma cornutiforme Metoptoma cornutiforuie. 



simplex 



Billingsia saratogensis 



Matthevia variabilis 



Dicelloeephalus hartti Dikelocephalus pepiuensis. 



speciosus lodeusis. 



Ptycliopana calcifora Ptychoparia wisconsensis. 



(A.) saratogensis oweni (of Hall). 



As the result of the comparison of an extended series of specimens 

 from the Potsdam sandstone of Buckingham, Quebec, Messrs. Ami and 

 Sowter concluded that Scolithits linearis and S. canadensis were iden- 

 tical species; the main differences existing between the two being 

 principally in the preservation, S. canadensis occurring in hollow tubes 

 or burrows, while S. linearis occurs as casts of the interiors of burrows 

 or holes. 6 



In 1890 Mr. C. D. Walcott described 7 the following species from the 

 limestone in the vicinity of Saratoga Springs, New York: 



Platyceras hoyti, p. 268. 

 Trochus? saratogensis, p. 268. 

 Agraulos saratogensis, p. 276. 



1 Potsdam fauna at Saratoga, New York. Science, vol. 3, 1884, pp. 136, 137. 



2 Notes on a fossil track from the Potsdam sandstone of northern Now York State. Canadian Nat. 

 new ser., vol. 10, 1883, pp. 466. 467. 



3 Impressions on Potsdam sandstone. Science, vol. 1, 1883, p. 177. 



4 Note on some obscure organisms in the roofing slates of Washington County, New York. 39lh 

 It. -p. N. Y. State Mns. Nat. Hist,, 1886, p. 160, pi. 1 1, fig. 1, 2. 



5 Second contribution to the studies of the Cambrian faunas of North America. U. S. Geol. Survey, 

 Bull. No. 30, 1886, p. 21. 



6 Report of the geological branch [of Ottawa Field Naturalists' Club]. Ottawa Naturalist, vol.1, 

 1887, pp. 96, 97. 



7 Description of new forms of Upper Cambrian fossils. U. S. Nat. Mus., Proc, vol. 13, 1890, pp. 276-279. 



