300 ROYAL SOCIETY OF CANADA 
Tangential—Rays of two kinds; the uniseriate rays low, inconspicuous, not 
numerous; the multiseriate rays numerous, resinous, lenticular, up- 
wards of 5 cells wide, the terminals not prolonged, the cells all of 
one kind and chiefly thin-walled. 
1007 
12 Of 1905. Exocrnous woop. UNDETERMINABLE. 
, A, 

This number represents two fragments of wood a few centimetres 
square. One is a separate fragment, carbonized throughout and evi- 
dently a piece of exogenous wood. ‘The other fragment, still adherent 
to the original matrix, is about 2-3 mm. thick, fully carbonized, and 
showing both growth rings and medullary rays. The material is too 
friable and too fully carbonized to make sections possible. 
1007 
55 8 of 1905. PHRAGMITES, sp. 
1 
Two fragmentary specimens of very imperfect leaves which cannot 
be referred to anything more definite than Phragmites. 
Aa of 1905. POTAMOGETON, Sp. 
Among the small fragments embedded in the general matrix of 
specimens from locality 1007, there were noticed several small, oval 
bodies, evidently of a composite character and very suggestive of the 
fruit of a Carex or one of the Naiadacew. Upon critical examination 
the conclusion was reached that they belonged to the latter family, of 
which Potamogeton was found to be the genus presenting the most 
favourable basis for comparison. From that point of view they were 
found to compare closely with such species as P. mysticus, P. confer- 
voides, P. obtusifolius, P. vaseyi, or P. diversifolius, being most directly 
related in point of size, form and variations with P. obtusifolius. The 
entire absence of foliage makes it impossible to correlate it any more 
definitely with existing species, and it is therefore unwise at present 
to assign any specific name. 
A review of the American history of this genus shows that on the 
whole, it has heretofore been recognized chiefly with respect to the 
Pleistocene formation, in which Penhallow (48, 49), and Dawson 
(6, 75) have recorded a number of species represented by their foliage. 
Knowlton (25) has similarly recorded the genus as occurring in the 
glacial deposits of West Virginia, but in all of these cases the plants 
found may be directly correlated with existing species. Lesquereux 
(42, 142, pl. xxili, f. 5—6) has recorded the existence of Potamo- 
geton in the Green River Group at Florissant, Colorado, where two 
species are recognized: the one, P. verticillatus, Lesq., being known by 
