1898J Whiteaves — On some Fossil Cephalopoda. 125 



which are known to have been collected at Stonewall were pre- 

 sented to the Museum, one by Mr. John Gunn, and the other by 

 Mr. \V. H. Robson. At the same time, also, Mr. Tyrrell obtained 

 a characteristic fragment of a specimen of this species, in situ, at 

 the Stonewall quarries. By far the most perfect of the specimens 

 yet received is the one presented by Mr. Gunn. It has two 

 entire volutions preserved, which are gyroceran rather than 

 nautilian in their mode of coiling, but very slightly asymmetrical. 

 The inner volution is openly coiled, the apex or initial point 

 being widely eccentric, and there is a large central perforation 

 about an inch and a quarter in diameter. 



These specimens seem to indicate a previously undescribed 

 species, which is here referred provisionally to Trochoceras rather 

 than to Lituitcs,\xv\W\ theshapeandrelativepositionof itssiphuncle 

 be ascertained, when it may have to be transferred to Plectoceras, 

 Peisvioceras or Discoceras. It differs from Lituitcs Bickmoreanus 

 Whitfield, (from the Niagara limestone of Indiana) which Hyatt 

 says is a Plectocetas, in its more openly coiled inner volution, in 

 its broadly elliptical and not subquadrate cross section, and in 

 its closer transverse plications, which are quite obsolete on the 

 periphery. Professor Whitfield, who has kindly compared two 

 of the best specimens from Stonewall with the types of his species, 

 thinks that the two forms are quite distinct. 



C. — From the Devonian I'ocks of Ontario. 

 Orthoceras Walpolense. (Sp. nov.) 



Shell small, longicone, straight, slender and increasing very 

 slowly in thickness, slightly and perhaps abnormally compressed. 

 Test unknown ; surface of the cast marked by thin acute, trans- 

 verse, annular ridges, which are much narrower than the grooves 

 between them. Septa, and shape and position of the siphuncle 

 unknown. 



The largest specimen known to the writer was collected 

 many years ago by J. DeCew in the Corniferous limestone of 

 Lot 6, Concession 14, of the Township of Walpole. It is about 



