FOSSIL COAL PLANTS. 45 



leaf, also magnified, showing the convergence of the nerves 

 of each fascicle into the teeth in which they terminate. 



I have not yet been able to determine whether these 

 leaves formed part of a compound frond, or whether they 

 were entirely'' simple. In the locality mentioned above, 

 they are i'ound in great abundance and in a fine state of 

 preservation — sometimes as many as a dozen being spread 

 out on a surface a foot square; but although I have exam- 

 ined several thousands of them, I have never detected any 

 distinct connection between them and any other fossil, 

 the extreme tenuity of the petiole having favored the 

 separation of the leaf from the parent stem. Nor do they 

 ever bear such relations to each other in position as to lead 

 one to infer that they had originally the verticillate 

 arrangement of the leaves of SpJienophyllum or Marsilea^ 

 which they slightly resemble in form. 



The plants most frequently associated with this fossil 

 are AletJiopteris lonchiiidis^ Alethopteris gracilis^ Trigon- 

 ooarpooi tricuspidatum^ SpJienopteris concinna^ &c., with 

 none of which could it have had any connection, I have, 

 however, seen mingled with the leaves of the plant in 

 question, slender stems which give off alternate petioles, 

 having much the character of the petioles attached to these 

 leaves, and I suspect we shall sometime find the two in 

 connection. 



The affinities of Whittleseya with other plants, whether 

 recent or fossil, are by no means clear. Among fossil 

 plants there are perhaps none with which it can be com- 

 pared, unless with Noggerathia and Py clinophylluin^ and 

 the differences from both these genera, which it presents, 

 are so striking as to render its relations to them doubtful. 



Among living plants, Salishuria, Marsilea and GTiamae- 

 Tops are the only ones in which I have noticed any points 

 of resemblance to our fossil, and all these are separated so 

 widely from it by other characters, that the comparison is 

 quite unsatisfactory. 



When we are able, from the discovery of all the compo- 



