254 



Shumard and other American palseontologists, but not of Martin ; though 

 it may prove to be a Martinia." 



Reticularia (?) sp. indet. 



" Foot of portage road : two specimens, each of which has the whole of 

 the dorsal valve and most of the ventral preserved, though the umbo and 

 beak of the latter are broken off. Both are transversely subelliptical in 

 outline and wider than long, and both have a rather shallow marginal 

 sinus in the ventral valve. They are entirely ribless, but the better 

 preserved one of the two is finely and nodosely cancellated by numerous, 

 close set, minute concentric ridges, that are crossed by similar radiating 

 ones. 



" At the portage road at the falls a specimen, with the same general 

 shape and with a similar sinus in the vental valve, was collected, but it 

 is so much worn that its surface markings are quite obliterated, and the 

 beak of the ventral is so imperfect that it is impossible to tell whether it 

 was originally perforate or not. This specimen seems to correspond fairly 

 well with E. Billings' figures of Athyris Blancha, from the Silurian 

 rocks of Maine, which Hall and Clarke refer to Meristina, but which 

 Schuchert says is a Meristella." 



Meristina (?) expansa, Whiteaves. 



Portage road at falls, one specimen ; and foot of portage road, an un- 

 usually large but imperfect specimen. 



The original description of this species is reprinted on page 245, ante. 



MOLLrSCA. 



Pelecypoda. 



Ambonychia undulata, Whitfield. (Sp.) 



Plate 28, fig. 4. 



Lcptodomus undulatiis, Whitfield 1878. Ann. Rep. Geo!. Surv. Wiscons. for 



1877, p. 81; &;(1880) Geol. Wiscons., vol. 

 TV, p. 293, pi. 18, figs. 1 & 2. 



Ambonychia utidulata, Whiteaves 1904. Geol. Surv. Canada, Ann. Rep., vol. 



XIV, pt, F, p. 46. 



"Portage road at falls, an imperfect left valve ; and foot of portage road, 

 a nearly perfect and very convex right valve. 



" Both of these specimens are marked with " strong, regularly rounded 

 concentric undulations." Mr. E. O. Ulrich, who has kindly examined the 

 five specimens of pelecypoda from the Ekwan River collected by Mr. 

 Dowling, and to whom the writer is indebted for some critical suggestions 



