200 WILLIAJISONIA. 



13,515. PI. III. Fig. 7. 



The base of a petiole, showing the clean-cut surface along which 

 the absciss layer was formed, cutting off the leaf from the persistent 

 portion of the petiole which remained attached to the stem. The 

 broad part of the leaf -stalk immediately above the base presents 

 a characteristic wrinkled appearance. 



Text-fig. 34. 



V. 3795. Several good fronds with very broad pinna? of the 

 form shown in Figs. 3 and 6, PI. III. The larger fronds are so 

 placed on this slab of rock as if converging towards a common point, 

 suggesting their original arrangement when attached to the stem. 

 In one corner of the rock there are portions of much smaller fronds 

 with narrower pinna? attached to an imperfectly preserved stem. 

 The foot-rule placed against the slab of shale shows the actual size 

 of the fronds. Also fragments of Brachyphyllum mamillare. 



39,285. PI. III. Fig. 6. 



Part of a frond 8 cm. long. This specimen illustrates the broad 

 type of pinna in which the base does not appear to be auriculate. 

 Scarborough. Bean Coll. 



V. 2510. A large slab with several fronds of W. pecten and 

 some twigs of Erachyphyllum mamillare. Labelled by Bean 

 Otopteris lanceolata ; this species, instituted by Phillips, is in all 

 probability identical with 0. acuminatus, and has nothing to do 

 with W. pecten. 



Lower Sandstone, Scarborough. 



V. 2619. A frond 24 cm. long and 1'5 cm. broad, bearing 

 closely crowded, obliquely set, narrow pinnas. Cf. 2889<z. 



Heckles Coll. 



V. 2889. Several good examples of long and narrow fronds 

 with closely set pinna? ; also part of a large frond with pinna? 

 in which the base is slightly auriculate at its upper edge. 



V. 3282. Two large slabs with numerous fronds illustrating 

 the variation in the size and form of the pinna? ; some isolated 

 bracts of flowers also occur in association with the fronds. 



V. 3516. In one frond the pinnae are long and narrow, like 

 those shown in Fig. 4, PI. III., with spreading veins at the base 



