OF LOWER GREEN SAND PLANTS. 



281 



Medullary ray-cells appear to be of at least two kinds : 

 (Vf) The majority of the cells are greatly elongated radially, 

 very narrow, and with pointed ends in transverse section 

 (1*1. XXX. fig. 2). These appear to be entirely thin-walled. 

 (6) Bordering some of the rays, and forming the uniseriate 

 termination to multiseriate rays, is a relatively small number 

 of wider, short, oval cells. These have somewhat thickened and 

 definitely pitted walls (text-fig. 86, bm.). 



AFFINITIES. The general arrangement of the tissue, the 

 broad and numerous narrower medullary rays composed of 



Text-fig. 86. Hythia Elgari, sp. nov. Radial section showing the cells of 

 the medullary ray ; m., narrow elongated cells forming the bulk of the 

 ray; bm.. broad, shorter, cells bordering the ray in some places with 

 thickened and pitted walls, p. ; v., vessels showing the scalariform pits. 

 No. V. 13232/. 



pointed narrow cells, the scalariform pitting of the vessels and 

 other details, are very suggestive of Fag us. On the other hand, 

 in the spec-ies of Fayus which I have been able to examine, the 

 ray-cells all have walls thickened to some slight degree at any 

 rate, in which pits are visible; while in the fossil the majority 

 of the ray-cells appear to be quite thin-walled, and thus to be 



