5o8 NEW YORK STATE MUSEUM 



The single other Beekmantown species with which this form bears 

 some similarity has been described by Professor Dwight [1884, 

 p. 255] asCyrtoceras Pdactyloides from the Beekman- 

 town at Rochdale in the Wappinger valley near the Hudson. That 

 species has, however, a relatively much larger siphuncle. 



(Cyrtoceras) acinacellum Whitfield (sp.) 

 Cyrtoceras acinacellum Whitfield. Am. Mus. Nat. Hist. Bui. 



1886. 1:327, pi. 27, figs. 10-13 



This interesting small form of which we have so far seen only 

 the type from the Fort Cassin beds at Fort Cassin is char- 

 acterized by the compressed section of the very slowly expanding 

 curved small conch, the relatively distant septa ( 10 in the space of 

 10 mm) which are very concave and show an abrupt high ventral 

 and a lower dorsal saddle. The siphuncle is small, tubular, with 

 short septal necks and long straight segments and subventran in 

 position. The outer shell is smooth or only possesses such sculpture 

 as the growth lines provide. 



From its section, the position and character of the siphuncle, we 

 surmise that this species may represent one of the primitive cyrto- 

 ceraconic genera of the Tarphyceratidae for which generic terms 

 have not yet been proposed. 



SPECIES RECORDED FROM PHILIPSBURG, CANADA 



Besides 



Sueceras marcoui Barrande (sp.) 



Tarphyceras farnsworthi (Billings sp.) Hyatt 



Aphetoceras farnsworthi (Billings sp.) Hyatt and 



Aphetoceras attenuatum Hyatt 

 there have been described by Billings from the Beekmantown beds 

 at Philipsburg in Missisquoi county, Canada, at the north end of 

 Lake Champlain the following species, whose generic position is 

 uncertain. 



Lituites imperator. Pal. Foss. 1 123 



Nautilus pomponius. Ibid. p. 26 



Orthoceras repens. Ibid. p. 312 



O. catulus. Ibid. p. 313 



O. perseus. Ibid. p. 313 



O. missisquoi. Ibid. p. 314 



O. cato. Ibid. p. 314 



O. catalina. Ibid. p. 315 



O. sayi. Ibid. p. 315 



O. xerxes. Ibid. p. 316 



O. tityrus. Ibid. p. 316 



O. aristides. Ibid. p. 316 



