TEMPSKTA. 151 



Corda^ has defined the species as follows: — 



" Rhachi tenui ; cortice tenui fuscescente ; fasoioulo vasorum 

 majori lunulato, sequali, utrinq[ue rotundato; minoribus oppositis, 

 recurvis." 



We may substitute the following diagnosis as probably more 

 in accordance with the real nature of the species : — 



Masse? of numerous branched adventitious roots, and a few 

 small ? petioles forming masses, occasionally several feet in 

 length, and in large specimens about one foot in diameter; the 

 transverfe section of the mass is often elliptical in shape, no doubt 

 as the result of pressure ; the ends of the specimens frequently 

 taper to a pointed termination, and the external surface may be 

 covered over with a layer of coaly substance representing car- 

 bonized tissue. The roots are of the diarc type, and the petiole 

 structures are characterized by a horseshoe-shaped vascular band. 

 (The central vascular axis possibly of the Protopteris form). 



Among the fossils collected by Mantell from the "Wealden rooks 

 of Tilgate Forest, Messrs. Stokes and Webb ' described certain 

 specimens -which usually showed an attenuation towards each end, 

 and at times an encrusting shell of carbonaceous matter ; to these 

 was assigned the name Endogenites erosa. The appearance of 

 transverse sections was considered to indicate a Monocotyledonous 

 structure, and hence the generic term Endogenites ; the specific name 

 erosa having reference to the eroded appearance of the surface. 



The same fossil was alluded to by Mantell' in 1822, but without 

 any definite name. 



In Martin's work, cited in the synonymy, there is a footnote 

 stating the occurrence of a ailicified specimen near Mulsey. 



Mantell reproduces Stokes and Webb's figures, and quotes the 

 opinion of Brongniart that these peculiar Wealden fossils have 

 some resemblance to fern stems. In Fitton's important Memoir* 

 we find several figures of specimens of the same fossil from the 

 neighbourhood of Hastings, and with a much more complete 

 description than that previously given by Stokes and Webb. 

 Special attention is drawn to the frequent occurrence of an in- 



1 Flor. Vorwelt, p. 83. 



' Trans. Geol. Soc. ser. ii. vol. i. p. 423. 



'^ Fossils S. Downs, p. 22. 



* Trans. Geol. Soc. ser. ii. vol. iv. p. 17, pis. xix. and xx. 



