THE OLD RED SANDSTONE. 137 
of Forfarshire. (See Plate XI., fig. 1.) It is a terminal 
flap* — one of several divisions — curiously fretted by scale- 
like markings, and bearing on its lower edge a fringe, cut 
into angular points, somewhat in the style of the Vandyke 
edgings of a ruff or the lacings of a dead-dress. It may be 
remarked, in passing, that our commoner lobsters bear, on 
the corresponding edge, fringes of strong, reddish-colored 
hair. The form altogether, from its wing-like appearance, 
its feathery markings, and its angular points, will suggest to 
the reader the origin of the name given it by the Forfarshire 
workmen. With another such flap spreading out in the con- 
trary direction, and a periwigged head between them, we 
would have one of the sandstone cherubs of our country 
churchyards complete. 
There occur among the other organisms of Balruddery 
numerous ichthyodorulites—fin-spines, such as those to 
which I have called the attention of the reader in describing 
the thorny-finned fish of the lower formation.t But the ich- 
thyodorulites of Balruddery differ essentially from those of 
Caithness, Moray, and Cromarty. ‘These last are described 
on both sides, in every instance, by either straight, or slightly 
curved lines; whereas one of the describing lines in a Bal- 
ruddery variety is broken by projecting prickles, that re- 
semble sharp, hooked teeth set in a jaw, or, rather, the entire 
ichthyodorulite resembles the sprig of a wild rose-bush, 
bearing its peculiar aquiline shaped thorns on ove of its 
sides. Buckland, in his Bridgewater Treatise, and Lyell, in 
his Elements, refer to this peculiarity of structure in ichthy- 
odorulites of the latter formations. The hooks are invariably 
ranged on the concave or posterior edge of the spine, and 
were employed, it is supposed, in elevating the fin. Another 
ichthyodorulite of the formation resembles, in the Gothic 
* See Note H 2. * See Note G 2. 
