200 WILLIAMSONIA. 



13,515. PI. IIi: Fig. 7. 



The base of a petiole, stowing 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 pinnse 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 pinnae 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 Braohyphyllum mamilla/re. 



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 Braehyphyllwm mamillwre. Labelled by Bean 

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

 probability identical with 0. aeuminatus, 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 pinnae. Cf. 2889a. 



Beckles Coll. 



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

 with closely set pinnae ; also part of a large frond with pinnae 

 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 pinnae ; some isolated 

 bracts of flowers also occur in association with the fronds. 



v. 3516. In one frond the pinnee are long and narrow, like 

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



