148 Dr p. Murray on the ArbuscvlUes argentea,from the 



articulations, grooved longitudinally, and composed of a bright 

 silvery cortical case, and a solid axis of carbonate of lime, fre- 

 quently crystallized. It differs decidedly from the crinoidal 

 animals, v. hich are regularly articulated ; and varies nearly in 

 the same degree from the corallines, &c. by not displaying the 

 cellular structure characteristic of that family, from which I 

 should at once have separated this fossil, were I not fully aware 

 of the extreme minuteness of those cells, and that occasionally 

 they are lost to observation by the denuding of the cortical in- 

 tegument, or shrinking of the polypus itself Besides, the fos- 

 silized objects under consideration are so rare and so imperfect, 

 that it would be premature, nay presumptuous, as yet to re- 

 move them from all the known classes, until we shall be jus- 

 tified by careful and repeated examination of other and more 

 perfect specimens. I would therefore, for the present, prefer 

 placing it among the corallines, under the third order of the 

 first class of Lamouroux, which are " Polypida plant-like, tu- 

 bular, simple or branched, never articulated ; of a horny or 

 membranous substance, but sometimes slightly covered with a 

 calcareous layer, neither cellular nor porous. Polypida situated 

 at the extremity of the stems." 



But as our Fifeshire fossil assuredly does not belong to any 

 of the genera of Lamouroux, we must class it as a new one, and 

 may give it the generic appellation of Arbusculites, from its 

 shrub- like appearance ; and, for a trivial name, argentea, from 

 its singularly metallic and silvery aspect. 



It occurs., as has before been remarked, in the mountain 

 limestone of the coal formation at Kirkcaldy, in Fife, and is re- 

 peatedly crossed by sections of encrinital stems and arms, which 

 abound in that locality. Indeed, I do not recollect ever to have 

 seen entrochinal fragments, he. in greater abundance than in the 

 grey carboniferous limestone of Innerteil, near Kirkcaldy. I 

 have &a\A Jragments of crinoidese; for stems of any length, or 

 shewing side-arms, are but rarely there to be met with. How- 

 ever, various shells of the genera Producta and Spirifera, cha- 

 racteristic of the for .nation, are very plentiful, with Caryophyl- 

 ites; and occasionally a very delicate Retepora, which is beau- 

 tifully crystalline, and white, and finely displayed upon the 

 dark grey coloured limestone. 



I 



