MATONIDIUM. 



Type. Large specimens of sterile and fertile segments. In the 

 Berlin Collection. 



Fronds of similar habit to those of Matonia pectinata, R. Br., 

 fan - shaped or pedate, with pinnate or pinnatifid pinnae, the 

 ultimate segments linear, slightly falcate, bluntly pointed. Son 

 numerous on the under side of the ultimate segments, in two rows, 

 one row on each side of the prominent midrib, circular or oval in 

 form, covered by an indusium attached to a short central columnar 

 receptacle, which bore the sporangia arranged in a circle. Sporangia 

 with an oblique annulus. 



The specimens of Matonidium Goepperti hitherto discovered do 

 not afford any satisfactory evidence as to the exact number of the 

 sporangia, nor do we know in detail the character of the venation. 

 It would appear that the sporangia were more numerous in each 

 sorus than in the recent species, and so far as is known the 

 venation appears to agree with that in Matonia pectinata. 



Reference may be made to Vol. I of the Wealden Catalogue 

 for remarks on the synonymy of this species. The plant named 

 by Phillips Pecopteris cccspitosa, and described by him in his 

 Geology of Yorkshire, is included as a synonym of Matonidium 

 Goepperti in my former list, but an examination of the type- 

 specimen in the York Museum has convinced me that Phillips' 

 specimen must be referred to the genus Laccoptcris. 



V. 3660. PI. XI. Fig. 3. 



The characteristic disposition of the long narrow pinnae is clearly 

 shown, but the petiole itself has not been preserved. Portions of 

 nine pinnae are seen, the longest measuring 16'5cm. in length and 

 about 1 cm. broad, tapering very gradually towards the distal end. 

 The segments are crowded, narrow, and falcate, with a slightly 

 obtuse apex. The lower surface of the pinnae is represented 

 in the drawing; in each pinnule the midrib forms a prominent 

 ridge, on either side of which there are indistinct depressions 

 marking the position of the son. The whole surface of each 

 segment appears to have been covered with crowded son, as in 

 the specimen shown in Text-fig. 7, A. In some of the segments 

 a small umbo in the centre of the soral depression marks the 

 position of the receptacle. 



