1903] Canadian Specimens OF LiTuiTES Undatus. 121 



as it is with any iTustration, is insufficient to show whether it is 

 synonymous with P. Foordi or distinct therefrom. 



In the Black River limestone of Ontario and Quebec there are 

 two other species of cephalopoda that may belong to the genus 

 Plectoceras, though the few specimens that have yet been found 

 of each do not give any indications of the shape or position of the 

 sipuncle. 



One of these is a large specimen from Kingston, Ont., and its 

 immediate vicinity, of which the writer has seen three specimens. 

 Two of these are still in the Museum of Queen's University, and 

 the other has recently been acquired, by exchange, from the 

 authorities of that institution, for the Museum of the Geological 

 Survey. All three, upon the whole, agree very well with Emmons' 

 two figures of Inachus undafus, and with Hall's representations of 

 Lituites undatus on Plate XIII, fig. i, and Plate XIII bis of the 

 first volun-e of the Palaeontology of New York. But the writer 

 has not seen any Canadian fossil that exactly corresponds with the 

 original of Plate XIII. fig. 3, of that publication, in which the 

 siphuncle is represented as placed at a short distance from the 

 venter, as in P. Jason. The two specimens in the Museum at 

 Queen's show only traces of the surface markings, and the sutural 

 line of one of them is cuved concavely and shallowly backward 

 on the siJe preserved, and not parallel to the obscure plicae. 

 The specimen now in the Ottawa Museum is a cast of the 

 interior of the septate portion of the shell, five inches and a half 

 in its maximum diameter, with fragments of the test attached. 

 Its outer volution is subquadrate in transverse section, and the 

 surtural lines are nearly straight on the sides but shallowly con- 

 cave on the venter or periphery. It is doubtful whether these 

 specimens should be called Eurystomites undatiis (Emmons) as sug- 

 gested by Hyatt, or Plectoceras widattim (Emmons). 



The other is the Gvroceras [Lituites) vagrans of Billings ( 1857) 

 from La Petite Chaudi^re Rapids, near Ottawa city, and near 

 Mile End, Montreal. Of this species the writer has only seen two 

 specimens, both from La Petite Chaudiere. The more perfect of 

 these is the type of the sp«icies, a very imperfect and badly pre- 



