CONIOPTEHIS. 109* 



PL XVII. The apices of the pinnae shown in Fig. 1 are identical 

 with those of Fig. 2, and the less deeply cut and rather broader 

 pinnules in Fig. 2 are connected with the more deeply cut 

 segments of Fig. 1 by transitional forms met with here and there. 

 I have no hesitation in regarding the fronds of Figs. 1 and 2 as 

 those of one plant, or at least of one species. That shown in 

 Fig. 1 is identical with Heer's Thyrsopteris Maakiana, but it is 

 connected, by slightly larger forms, with S. hymenophylloides, 

 Brongn., and with S. arguta, L. & H. ; the frond of Fig. 2 

 agrees exactly with some of the published figures of S. Murray ana, 

 S. ajfinis, Phill., and other ' species.' The difference between 

 Figs. 1 and 2 is far less than one finds between fronds on the 

 same plant of several recent ferns. 

 Cf. Scleropteris tenuisecta, Sap. 1 



39,261. PL XXI. Fig. 1. 



This specimen illustrates a further point confirmatory of the 

 specific identity of the fronds with sharper and longer pinnules 

 with those bearing the more rounded and shorter segments. In this 

 pinna the segments are of the former type, as in S. hymenophylloides, 

 Brongn. ; but at the base of the pinna the two lowest pinnules 

 are curiously modified and have a form suggestive of an Aphlebia- 

 type of lamina, the lamina being much more deeply cleft and 

 tlu- narrow linear divisions much longer and more spreading. 

 Exactly similar Aphlebia-likc segments are met with on pinnae 

 bearing the shorter and more rounded pinnules. 



Cf. Sphenopterts minutula, Sap. 2 



Scarborough. Bean Coll. 



52,597. PL XXI. Fig. 2. 



This pinna is of the same type as those shown in PL XVI. 

 Fig. 6 and in PL XX. Fig. 2. The lowest pinnule on the left- 

 hand side exhibits a long branched segment like the Aphlebia 

 form in the preceding specimen (PL XXI. Fig. 1). 



1 Saporta (91), pi. Ixi. 



2 Ibid. pi. Ivi. Cf. also Alloiopteris qiiercifolia (Goepp.), as figured by 

 Potonie (99), p. 139. 



