534 Henry Hicks — Fossil Plant-remains of St. David" s. 



vertical wall) without evidence of any relative planes, except the 

 very short and secondary one on the left. Yet, between conditions 

 of this kind and true stalactitic agates, there is a gap which at 

 present I cannot bridge. The mural agate consists of concretions 

 in flat planes, formed irrespectively of gravity ; the stalactitic agate, 

 of concretions on central rods, formed with reference to gravity. 

 I have, indeed, one example in which these central rods are incipient 

 in formation ; — are as fine as hairs, and are connected, as in Fig. 6, 

 by drooping branches concurrent with the successive outlines of the 

 falling mass ; and another, Fig. 7, in which the tubes of a folded agate 



Fig. 7. 



Fig. 6. 



have become crystalline, and are clearly minded to determine them- 

 selves into straight lines. But these are both small, and of structures 

 too unusual to found reasoning upon. I shall engrave them, however, 

 hereafter, but before examining these and the other structures illus- 

 trating the connection between mural and stalactitic agates, it will 

 be better to trace the closer connection on the other side between 

 mural and conchoidal agates. The states intermediate between these 

 two will be the subject of my next paper. 



II. — Notes on a Species of Eophyton (?) prom the Lowee Akenig 

 EocKS of St. David's. 



By Henry Hicks, Esq. 



(PLATE XX.) 



AS none of the figures hitherto given of the genus Eophyton 

 show either its internal structure, or articulations of its stems, 

 and as I am in possession of a specimen from the Lower Arenig 

 Eocks, of Eamsey Island, near St. David's, which resembles in some 

 respects the Eophyton Linnceanum Torell, but which shows both 

 articulations of the stem, and an internal vascular structure, a de- 

 scription of the species may probably be useful, and may tend to 

 elucidate the true nature of Eophyton, concerning which so much 

 doubt seems to exist at present. 



