AVILLIAMSONIA. 197 



a. FRONDS. 



48,732. PI. III. Fig. 1. 



The figure shows a small portion of a specimen 11 -5 cm. in 

 length. This affords a good illustration of the narrow form of 

 leaf with very small pinnae, similar to the type figured by Lindley 

 and Hutton as Pteropkyllum pecten. 1 



V. 3517. PI. III. Fig. 2. 



This example illustrates a somewhat different form of frond, 

 in Avhich the pinnae are short and relatively broad; the breadth 

 of the specimen, which has a length of 14 cm., is very uniform. 

 At the base the pinnoo measure 4 mm. in length, and those at 

 a higher level have a length of 1'3 cm. ; the segments have 

 rouudcd bases, and are attached along the middle of the upper 

 face of the rachis. A piece of a leaf having much narrower pinnae 

 occurs in close association with the example shown in the figure. 



Upper Shale, Scarborough. 



V. 3519. PI. III. Fig. 3. 



The figure represents the apex of a frond 30 cm. long and 

 5-5 cm. broad ; there are several other leaves of this species on 

 the same piece of rock, some of them agreeing with the specimen 

 shown in Fig. 2. These pinnae (Fig. 3) are fairly broad, and 

 in some of those nearer the lower part of the frond the upper 

 edge of the base is slightly lobed or ' eared.' The apices are 

 acuminate, the lower edge of the pinnae being more strongly 

 curved towards the tip than the upper. There is a close 

 resemblance between the apex of the frond, as shown in the 

 figure, and that of O'toza mites gramineus, Phill., 2 but in Phillips' 

 specimen (now in the Leckenby Collection, Cambridge, No. 216) 

 the pinnae are of the Otoza mites type. Several other fronds occur 

 on the same slab with that of Fig. 3. Labelled by Bean Otopteris 

 lanceolata. 



Lower Shale, Scarborough. Bowerlank Coll. 



1 Lindley & Hutton (34), pi. cii. 



2 Phillips (75), p. 223. 



