90 TODITES. 



with regard to the identity of these ferns, 1 and Brongniart 2 himself 

 speaks of the "extreme affinite " of the two species. The specimens 

 referred by Phillips and Lindley & Hutton to Pecopteris recentior 

 differ from Brongniart's Pecopteris Williamsonis in the larger and 

 longer pinnules, but an examination of several large fronds in 

 various collections has convinced me of the identity of the two 

 forms. Specimens of undoubted Todites Williamsoni are often met 

 with in English museums bearing the name Pecopteris recentior, 

 given to them by Bean and other contemporaries of Phillips and 

 Lindley & Hutton, and there is no doubt that the examples 

 so designated are simply the lower parts of large fronds of 

 T. Williamsoni. Phillips' figure of what he names Pecopteris 

 curtata represents the characteristic fertile pinnules of Todites. 



The type-specimens of Pecopteris dentata, L. & H., were fortu- 

 nately discovered in the Williamson Collection in the Manchester 

 Museum ; 3 they exhibit the characteristic pinnae and closely set 

 short and broad segments of Todites Williamsoni, agreeing exactly 

 with such specimens as 39,250 (PI. XIV. Fig. 7), V. 3654, and 

 others, and with the figures of Pecopteris whitbiensis of Brongniart. 



In 1836 Groppert adopted his generic name Acrostichites for 

 Pecopteris Williamsonis, on account of the manner of occurrence of 

 the sporangia as shown in the figure of Lindley & Hutton. Many 

 authors have retained this genus, but as Schenk and Raciborski 

 have demonstrated, the structure of the sporangia clearly points 

 to the inclusion of the species in the Osmundaceae ; the sporangial 

 characters being such as we are familiar with in Todea and 

 Osmunda. 



The figures given by Zigno of a portion of a fertile bipinnate 

 frond, which he names Dichopteris microphyllaf bear a striking 

 resemblance to Todites, and it is probable that the Italian plant 

 is specifically identical with the present species. There is a close 

 agreement between Acrostichites Goeppertianus 5 from the German 

 Rhaetic beds and Todites Williamsoni, but there are certain small 



1 Nathorst (80 1 ), p. 57. 



2 Brongniart (28 2 ), p. 323. Of. pi. ex. fig. 4, and pi. cix. figs. 2-4. 



3 Since this was written the type - specimen has been refigured ; vide 

 Seward (00), pi. i. 



4 Zigno (56), pi. xv. fig. 5. 



5 Schenk (67), p. 45 ; pi. v. fig. 5 ; pi. vii. fig. 2. 



