118 DIPTEEIDIN.aE. 



straight and slightly lobed ; those nearer the distal end of the- 

 pinnae are entire, more inclined to the pinna axis, and more 

 acutely pointed. 



Upper Shale, Scarborough. Bean Coll. 



39,239. PI. XVI. Figs. 3 and 3. 



This specimen serves as an example illustrating the close 

 agreement between portions of a frond of Coniopteris arguta and 

 KluJcia exilis. Of. the drawing of Pecopteris acutifolia given by 

 Lindley & Hutton (Fossil Flora, pi. clvii.). 



V. 3677. Text-fig. 16. 



Portions of two of the best fertile pinnsa are shown in the 

 drawing. The fertile segments are about 4 mm. in length, and 

 the indusial cup, with a small central receptacle, has a diameter 

 of 1 mm. Cf. Aspleniopteris pinnatifida, Font. 1 



39,255. Labelled by Bean Neuropteris arguta. This example 

 is probably part of a large pinna ; it agrees closely with the 

 specimen figured by Lindley & Hutton as Sphenopteris serrata, 

 and forms a connecting link between the fronds with smaller 

 pinnules and those with larger ultimate segments. 



Scarborough. Sean Coll.. 



Other specimens : V. 2632, V. 3B32, V. 3941, 13,487, 13,493,, 

 39,232, 39,260, 40,467. 



Family 



This family name is employed to indicate the probable close- 

 relationship between the recent genus Dipteris and such fossiL 

 genera as Dictyophyttum and Protorhipis, and to give expression to 

 the deviation of these ferns from the typical Polypodiacea?. 



1 Fontaine (89), pi. xxv. fig. 6. 



