390 MR ROBERT KIDSTON ON THE FOSSIL FLORA OF THE 



Megaphyton, Artis. Antediluvian Phytology, p. 20, 1825. 



Megaphyton frondosum, Artis. 

 Plato XXVI. fig. 4. 



Megaphyton frondosum, Artis, Antcdil. Phyt., pi. xx. 

 Megaphyton frondosum, KiJston, Catal. Palaoz. Plants, p. 143. 

 Megaphyton approximation, L. & H., Fossil Flora, vol. ii. pi. cxvi. 

 Megaphyton distans, L. & H., Fossil Flora, vol. ii. pi. cxvii. 



Remarks. — Some notes on this fern stem will be found in my Catalogue of 

 Palcvozoic Plants, where the difficulties in the limitation of this species are 

 indicated. 



Locality ; — Kadstock. 



Megaphyton elongatum, Kidston, n. sp. 

 Plate XXVI. fig. 1. 



Description. — Frond scars arranged in two opposite vertical rows, distant ; 

 those of one row alternative with those of the opposite corresponding vertical 

 row. Frond scars elongated, rounded at their upper extremity, and gradually 

 merging into the stem below. Vascular cicatrice oval, situated towards the apex 

 of the scar. Stem striated, and bearing numerous cicatricules of aerial rootlets. 



Remarks. — This species is the most frequently occurring fern stem in the 

 Radstock Series, but in mentioning this it must not be inferred that the fossil 

 is plentiful. One specimen from Radstock, removed from its matrix, is 3 feet 

 11 inches in length, and at one extremity is 5 inches across, and at the other 

 extremity 3f inches ; the distance between the top of one scar and the top of 

 that immediately succeeding it varies from 7 to 8 inches in this example. On 

 another specimen the summits of the scars are about 10 inches apart. 



The example figured, of which the sketch is reduced one half, is in the 

 collection of the Bristol Museum. It does not show well the Megaphyton 

 character of the stem, but was selected for figuring on account of the frond 

 scar being more clearly defined on this specimen than on any of the compressed 

 stems that show the two opposite vertical rows of scars. 



The specimen I identified as Caulopteris Cistii, from Radstock, in the col- 

 lection of the British Museum, is probably a fragment of a stem of this species. 



Localities : — Radstock ; Middle Pit ; Camerton. 



Caulopteris, Lindley & Hutton, Fossil Flora, vol. i. p. 121, 1832. 



Description. — Stems of arborescent ferns, bearing distant or contiguous, 

 circular or oval, smooth sars, arranged quincuncially, containing : — Type 1. An 

 inner circular or oval closed ring, more or less following the contour of the frond 

 scar; within this is a second oval scar, open at its upper aspect, the free ends being 

 bent inwards, and forming a "horse-shoe scar." Type 2. A closed inner circular or 



