101 
TAB. CCLI. 
LITHOMARGA. 
_ Class 2. Earths. Order 2. Mixed. 
Syn. Lithomarga. <Kirw. 1. 187. 
Argile lithomarge, Argilla crustacea. Waller, 
140. ae : 
Stein-mark. Emmerl. 1. 355. 
La Moelle de Pierre, oula Lithomarge. Broch, 
1. 447, 
Tue substance which I find generally termed Lithomarga 
seems to be an argillaceous Steatite or Steatitic Clay. I 
gather this from the descriptions in different authors, al- 
though some are doubtful as to its containing Steatite or 
Magnesia, which generally gives an additional soft or soapy 
quality to it. The present specimens are from near Keswick 
in Cumberland. The provincial name is Moidal.—It more 
or less adheres to the tongue as it is loose, or indurated, 
and some parts of these specimens are more so than others, » 
The Lithomarga feels smooth, with a slippery softness, its 
looser parts soiling the fingers and the harder parts not, 
the former readily making a streak on paper or any such 
substanee. 
The vulgar tdea of Rock Marrow seems curiously analo- 
gous to the upper specimen, which resembles the bone also ; 
the lightish part representing the latter and the darker the 
marrow *. It resembles a soft Slate, and we sometimes find 
veins in Slate much resembling the lighter part; the central 
Figure is little else, coated with the grey variety as in the 
* This somewhat agrees with the description of the Rock-Soap of some 
zuthors, 
