129 



Sphenopteris furcata is figured at Plate CLXXXL, and 

 Sphenopteris crenaia at Plate XXXIX. of the " Fossil 

 Flora." The suggestion of the new specific name Lewisii 

 came too late to be acted on, as the issue of the " Fossil 

 Flora" was brought to a close in 1837. 



Letters from Professor W. C. Williamson, F.R.S. : — 



I. 



ScaeboeouGtH, November 28th, 1832. 



Sik, — I have at length been able to complete the promised drawings, 

 which I hope will be of use to the "British Flora/' as they are on a sub- 

 ject rather different to any you have yet described-— the following part of 

 the vegetable kingdom : — 



No. 1 is copied from a fragment of a large stem which, when perfect, 

 measured about three feet in length, but owing to its being- compressed so 

 flat and thin, and to the hard nature of the rock where it was embedded, 

 it could not be got out entire. At its top it was about three and a quarter 

 inches in diameter : it is grooved or sulcated longitudinally, the grooves 

 becoming more indistinct as they approach the lower end, which increased 

 to about three and a half inches in width. It is divided into joints from 

 four to five inches long at the upper part, but they become shorter as they 

 are nearer the root. The leaves, of one of which there is a small frag- 

 ment shown in the drawing No. 1, are found crushed and broken in 

 immense quantities by the side of the stem, but never attached. My 

 father [the late Mr. Williamson, of Scarborough, who died on the 15th 

 July, 1877,- at the age of ninety-three] has seen them upwards of two 

 feet long and neither of the ends perfect. How much longer they may 

 have been we cannot say. The Petiole is deeply sulcated longitudinally, 

 and is nearly half an inch in width ; it is frequently decomposed, and the 

 residuum is a white powder which falls out when exposed to the air. The 

 Folioles are long and pointed, strongly sulcated in the same manner as 

 the Petiole to which they are attached by the whole of their base. 



The Flowek, Fig. 2, is round and bulky. The petals are long, 

 smooth, and lanceolate, curling outwards towards the stalk. From the 

 base of the petals to the edge of where the receptacle has been, is deeply 

 and irregularly striated. There is a perforation through the stem where 



