A Last of Minerals and Organic Remains. 83 
No impressions of fish nor of vegetables have hitherto been 
discovered in the Canadas. - 
Trilobite——This family is universal, astonishingly nu- 
merous, and very diversified in its forms. It is always in 
fragments ; but which, however, not unfrequently, are the 
greater part of the fossil, and with the remainder close by. 
ave not seen the genus Calymena of Brongniart onthe 
north side of the St. Lawrence. ‘The genus asaphus is the 
most general and the most perfect. The A. caudatus and 
laticaudatus are met with in most situations (rolled on north 
shore of Lake Superior, Rainy River, Lake of the Woods, 
&e.) Many of this genus differ from those of the above 
author, in the number of articulations: an asaph from Gas- 
Be in my collection, given me by my friend Mr. Buchanan of 
ontreal, has fifteen, instead of from eight to twelve artic- 
ulations, the extremes allowed to this genus: the end of 
the cauda in this specimen is bent backwards. Others are 
distinguished by a double g d edging 1theabd 
(Lake Erie.) Many asaphi from Montreal, Lakes Simcoe 
and Ontario have a smooth coatof limestone, granular or spar- 
ry, which conceals the abdominal joints and lobes and ex- 
hibits only the relieved outline of the cast; but in a few, 
their structure is still discernible ; as is well exemplified in 
a superb specimen in the possession of Dr. James of Alba- 
ny ; in which, in fact, the greater part of this covering has 
disappeared. The largest American asaph which I have 
seen is that of Dr. James’. I have the greater part of one 
from Gaspé three inches long by three and a quarter at 
the broadest part. They are nearly of this size at Mon- 
treal, much smaller at lake Simcoe, and although often of the 
common size (one to one anda half inch in diameter,) in the 
Lake of the Woods, are almost a both there and 
inthe Bay of Quinte, Lake Ontario. They occupy indis- 
eriminately limestone of every colour, but are most nume- 
rous in the brown crystalline. They are composed of the 
limestone in which they happen to be imbedded. 
_ Dr. Mitchell, of New York, has an asaph from Anticosta, 
in the Gulf of St. Lawrence. 
The calcareous rocks of the north shore of Lakes Hu- 
ron and Simcoe, besides the asaph, are full, in patches of 
the debris of very large trilobites ;—but too small to allow of 
the determination of the genus. Ihave, however, met with 
