OF THE EASTERN BORDERS. 305 



parallel with the margins. This is the remains of some succulent 

 plant ; it has somewhat the aspect of a Crinum leaf. The fragment 

 figured is interesting, as, attached to it, are four marine Annelids — 

 the Spirorbis carbonarius, in different stages of growth. Although 

 we have obtained hundreds of marine shells from the Budle shale, 

 we have never seen the little Annelid there, excepting upon these 

 leaves. In other places this marine animal has been found amid the 

 remains of the vegetation of the Carboniferous era ; we have met 

 with it at Tweed Mill along with Coniferous stems ; it appears upon 

 Fern fronds at Burdie House ; and Mr. Binney has noticed it in the 

 Lancashire Carboniferous beds. 



Acrogenous Plants. 

 FiLiCES or Ferns. 



We, for the most part, have been wandering among strange forms, 

 having no near resemblance to existing vegetation ; we come now to 

 relics which associate themselves with familiar friends, and which 

 inexperienced observers might mistake for entombed specimens of 

 some of our commonest plants. Ferns, distinctly recognisable, are 

 found in vast profusion in most coal-fields. So numerous are they 

 in species, that of the 300 Carboniferous plants in Great Britain, 140 

 are Ferns ; and so abundant in the aggregate, that many shale beds 

 are crowded with their remains. When hving they are graceful and 

 attractive objects, and even when raised from their sepulchres they 

 are still beautiful, their elegant forms being well displayed between 

 layers of shale, where they are spread out with as much exactness 

 as recent Ferns in a herbarium. 



Fossil Ferns usually occur in detached fronds and leaflets ; and 

 though the veins of the leaflets are frequently preserved, it is rare 

 indeed that any remains of the fructification are discovered. In the 

 absence of fruit, the form of the frond and of other parts of the Fern, 

 and the mode in which the veins spread through the leaflets, are 

 taken as characters to discriminate the various genera. A few short 

 round or compressed fossils, with large oblong scars, have been found 

 in Carboniferous beds. There is little doubt of these being the 

 remains of Tree Ferns such as now grow in moist climates, chiefly 

 on the borders of the tropics. Professor King informs us, that he 

 has obtained stems of this character from the coal-measures at 

 Jarrow and Felling, associated with, though not attached to. Fern 

 fronds ; these fronds, therefore, not improbably were the foliage of 

 the arborescent Ferns. 



But while Ferns are abundant in coal-fields generally, exception 

 must be made for the Mountain Limestone formation of our district. 

 In the south-eastern part of Northumberland they are found in great 

 numbers ; they extend to Togston, a little south of the Coquet, where 

 fine specimens are in the shales ; but in the beds north of the Coquet 

 they are exceedingly rare, so rare that we have found them only in 



VOL. I. X 



