226 MR. HAMSHAW THOMAS ON THE FOSSIL FLORA OF ["June I913,. 



IV. Description of the Species. 

 (i) PTEBJDOPHYTA. 



Equisetales. 



Equisetites colemnaris (Brongn.). 



['Hist. Veget. Foss.' 1828, p. 115 & pi. xiii.] 



This species is represented by several sandstone casts of parts of 

 leafy shoots. These are mostly about 3 cm. in diameter, and show 

 the usual leaf-sheaths at the nodes, with united leaves about 

 2 cm. long, but becoming free at the tips. A sandstone cast of a 

 single leaf-sheath in Mr. Saunders's collection has a diameter of 

 about 4 cm., and evidently belonged to a very large stem. The 

 leaves are about 2 mm. broad, and show at their bases cushion- 

 shaped structures, perhaps representing part of the cortex, and 

 somewhat similar to those recently figured by Prof. Seward from 

 Afghanistan. 1 



I have seen no specimen from JVlarske that can be identified 

 with certaint}' as Equisetites heani, but good examples of the latter 

 occur frequently at Eoseberry Topping. 



Hydropteridese (?). 



Sagenopteris phillipsi, var. major Seward. (PL XXV, fig. 2.) 

 [' Jurassic Flora York's.' Brit. Mus. Catal. vol. i (1900) pp. 162, 169 & fig. 26.] 



A number of separate leaflets have been found which are of an 

 unusually large form. Several of the incomplete specimens are 

 5 cm. long, and one of them is 7 cm. long and 4 cm. broad 

 (see PI. XXV, fig. 2). There is a well-marked midrib, though in a 

 few cases this is not conspicuous, and the venation is of the usual 

 anastomosing character. The venation is coarser than that usually 

 seen in 8. phillipsi. The specimen here described may be com- 

 pared with the examples figured by Prof. Seward. 



Filices. 



Laccopteris polypodioides (Brongn.). 



[' Hist. Veget. Foss.' 1828, p. 372 & pi. lxxxiii, fig. 1.] 

 This species is represented by a few small fragments of fertile 

 pinnules found in the grey clays and sandstone. They show the 

 usual characters of this form. The sori are arranged in two rows, 

 one on each side of the midrib. The individual sporangia are 

 not seen ; this may be an indication that they were covered with 

 an indusium. The veins are clearly seen, but do not show the 

 usual anastomosing. I have found many fragments similar to 



i Seward (12) pi. i, figs. 6. 7, & 9. The numerals in parentheses refer to 

 the Bibliography, § VI, p. 248. 



