222 THE CANADIAN NATURALIST. [May 



Southern Counties of New Brunswick, I ventured to express a 

 doubt as to the precise age of the Acadian carboniferous limestones, 

 for a few species collected in the vicinity of the Albert mines had 

 the same permo-carboniferous look as those at Windsor. Dr. J. 

 S. Newberry, in looking over my collection, was also impressed 

 with their permo-carboniferous fades. At his suggestion, I sent 

 a small collection of these fossils to Mr. Meek, who writes me as 

 follows : — "A small collection of these same fossils from Windsor 

 was presented to the Smithsonian Institution, by Dr. E. Foreman, 

 some three or four years since, and they have remained a puzzle 

 to me ever since, If they had been brought in from some unex- 

 plored region of the Rocky Mountains, for instance, I confess I 

 should have referred them to the horizon of the upper coal 

 measures, or to that of a series of rocks known in Kansas as the 

 permo-carboniferous, from the remarkable mingling in them of 

 coal measure and permian types there ; but in reading over the 

 able publications of Dr. Dawson, Sir Charles Lyell, and Mr. 

 Davidson, on the age of these Nova Scotian beds, I was led to the 

 conclusion that this must be one of those very rare cases where 

 physical structure shows palaeontology to be at fault. Although 

 I am not positively sure that any of the species are absolutely 

 identical with those of the higher horizon, these fossils certainly 

 present a remarkable permo-carboniferous look, and, when viewed 

 collectively, they are unlike the western sub-carboniferous fauna. 

 For instance, there are here from Windsor several good specimens, 

 showing both valves, with the surface markings of an Aviculo- 

 pecten undistinguishable by any characters yet observed from A. 

 OccidentaUs of Shumard (Peeten Cleavelandicus Swallow), one 

 of our most common and characteristic coal measure, permo- 

 carboniferous and permian species in the west, which, so far as 

 yet known, has never been found below the upper coal measures, 

 at any rate in the western localities. Another shell represented 

 in the collections from Windsor by casts, is very similar to 

 varieties of the so-called Mytilus squamosus from the English 

 permian. It has almost precisely the form, and agrees in size, as 

 well as in showing between the beaks the cast of a little depression 

 on a shelf or septum within the beaks, such as we often see in 

 species of Myalina, to which these shells doubtless belong. 

 Another little shell, from Windsor, is quite or nearly like a little 

 permo-carboniferous species in the west, known as SedpwicMa ? 

 concava. M. and H. ; while you have from the same casts of an 



