156 SPHENOPIERIS. 



€. hymenophylloides ; but other specimens exhibit certain, differences 

 •which seem to point to the retention of SpTienopteris Murrayana 

 for certain fern fronds agreeing with the examples figured by 

 Brongniart in figs 1, 2, and 4 of his pi. cxxvi.^ 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 pinnas being almost at right 

 ■angles to the rachis. 



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



The fragment illustrated consists of a secondary rachis bearing 

 short pinnse 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 a/rguta. 



Upper Shale, Scarborough. Bean Coll. 



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

 pinnse like that represented in Fig. 5. Labelled by Bean 

 Pecopteris Mwrrayana. 



Lower Shale and Sandstone, Scarborough. Bean Coll. 



V. 3287. Probably specifically identical with the above. 



Brongniart (28*). 



