A NEW SPECIES OF ACER. 327 



POTAMOGETON RUTILANS (?), WOLFGANG. 



A single specimen in a Green's creek nodule from the collection of Mr. J. 

 Stewart. It embraces the stem and several leaves. » 



This species is at present known only near Red Rock, Lake Superior, and 

 on Twin island, James's bay; in marshes on Anticosti ; and at the mouth of 

 the Nipigon river (Macoun). It would therefore appear probable that it 

 was more abundant in the past than at present. 



EQUISETUM LIMOSUM (?), L. 

 E. SYLVATICUM (?), L. 



Fragments of plants with lateral members in whorls were frequently met 

 with and, although not satisfactorily referable to any modern genus, pre- 

 sented the closest resemblance to the two species of Equisetum above named, 

 to which they are provisionally referred. 



MENYANTHE3 TRIFOLIATA, L. 



A specimen of the Leda clays from Montreal, now in the Peter Red path 

 Museum, shows the remains of a plant of which only the basal portion is 

 preserved. This consists of a central axis from which rather stout lateral 

 members are developed at right angles, and from which in turn are pro- 

 duced numerous fine roots. The specimens are of small diameter, but from 

 their evidently shrunken character must represent the remains of plants ap- 

 proaching one-quarter of an inch in diameter. Although not clearly refer- 

 able to any existing species, the resemblance to the stem of Menyanthes 

 trifoliata is very striking, and in all probability it represents a similar under- 

 ground stem with its roots developed at right angles to the axis of growth. 

 The absence of leaves renders a more accurate determination at present 

 impossible. 



Description of New Species. 



acer pleistocenicum, sp. nov. 



This fossil was recently obtained by Mr. Townsend from the Pleistoeene 

 of the Don river, Toronto, and was purchased by Sir Willam Dawson with 

 other specimens and presented to the Peter Redpath Museum. Though nol 

 perfect as to form, the leaf is beautifully cast in an argillaceous nodule, and 

 shows several details of venation quite perfectly. A drawing, giving a 

 restoration of the leaf, is herewith presented. From this ii will be aeen thai 

 the left half of the blade is nearly intact, while of the right half only about 

 two-thirds remain, the lobes being entirely cut off by fracture of the matrix. 



The leaf is evidently that of a maple, although of a type quite distinct 

 from any of our existing forms. As will appear from the figure, the general 



XLIII— Bull. Geol. Soc. A.m., Vol. 1, 188!). 



