FOSSIL FLOKA. 39 



PLATE XI. 



" Prostrate Hydatica." 



A SPLENDID specimen of another species of Hydatica, spread out on the surface of the coal- 

 shale, as if expanded on the bosom of the lake in which it grew : the length of the original, a 

 part of which only is figured in the plate, was eight feet, five inches. 



This species is named by ili-. Artis, Hydatica prostrata. The stem is jointed, and slightly 

 striated ; the joints are formed with irregular sutures, whence arise tufts of linear leaves 

 resembling those of our common grasses. 



Fragments of this fossU plant are abundant in the roofs of several of the chambers whence the 

 coal has been extracted, in Elsecar Colliery, Yorkshire. 



