156 SPHENOPTERIS. 



C. hymenophylloides ; but other specimens exhibit certain differences 

 which seem to point to the retention of Sphenopteris Murrayana 

 for certain fern fronds agreeing with the examples figured by 

 Brongniart in figs 1, 2, and 4 of his pi. cxxvi. 1 Possibly this 

 separation may prove to be artificial, but it is at least a convenience 

 to distinguish some of the Yorkshire ferns, which differ in a few 

 points from the typical Coniopteris hymenophylloides, by a distinct 

 specific designation. It is hopeless to attempt a complete synonymy 

 of Sphenopteris Murrayana as employed in the present sense, as 

 the greater number of the fossils so named by various authors 

 should be referred rather to C. hymenophylloides. As no specimen 

 exhibiting the vegetative characters which we associate with 

 S. Murrayana in its restricted sense has been seen with fertile 

 ^pinnules, the genus Sphenopteris is retained in preference to 

 Pecopteris or Coniopteris. 



The fronds of the S. Murrayana type appear to be characterized 

 by a spreading habit, and by the broad pinnae being almost at right 

 angles to the rachis. 



39,273. PI. XXI. Fig. 5. 



The fragment illustrated consists of a secondary rachis bearing 

 short pinna? with small pinnules having the Sphenopteris type 

 of venation, and agreeing fairly closely in form with those of 

 Coniopteris hymenophylloides. It is, however, quite possible that 

 such specimens as this may belong to the lower portions of large 

 Coniopteris fronds. Labelled by Bean Sphenopteris arguta. 



Upper Shale, Scarborough. Sean Coll. 



V. 3679. A large but imperfectly preserved frond, bearing 

 pinna? like that represented in Fig. 5. Labelled by Bean 

 Pecopteris Murrayana. 



Lower Shale and Sandstone, Scarborough. Bean Coll. 



V. 3287. Probably specifically identical with the above. 



1 Brongniart (28 2 ). 



