102 Proceedings of the Royal Physical Society. 
— 
X. On the Occurrence of Arthrostigma gracile, Dawson, in 
the Lower Old Red Sandstone of Perthshire. By ROBERT 
Kinston, Esq., F.R.S.E., F.G.S. [Plate IIT.] 
"(Read 15th March 1893.) 3 
In a paper published in 1877 by Messrs R. L. Jack and 
R. Etheridge, jun., is given an account of the “ Discovery of 
Plants in the Lower Old Red Sandstone of the Neighbour- 
hood of Callander,’! by Mr A. Macconochie. This com- 
munication is introduced by an excellent Bibliography of the 
Scottish Old Red Sandstone Flora up to the date of its 
publication, which is followed by a description of certain 
specimens from the Lower Old Red Sandstone of Perthshire, 
concluding with remarks on the Geology of the Old Red 
Rocks in the district specially dealt with. 
To a few of the specimens described in this paper, as 
Psilophyton sp., I wish to call further attention. 
Of these fossils two reduced figures were given—Fig. 1 from 
quarry, near Braeandam House, Callander, and. fig. 2 from 
south-west corner of Muir Plantation, near Braeandam 
House. 
Messrs Jack and Etheridge state, in regard to these speci- 
mens, that they were convinced of their great resemblance to 
and affinity with Dawson’s genera Psilophyton (especially 
P. princeps) and Arthrostigma, “our own conclusion being 
that the closest affinity was with the latter genus.” ? 
For the purpose of confirming or correcting their views, 
the better examples were submitted to Mr R. Etheridge, 
F.R.S.,and Mr W. Carruthers, F.R.S., and the latter furnished 
the less note on the specimens :— 
“They have a true Lepidodendroid structure. The axis 
consisted of a slender column of vascular tissue; the soft 
cellular tissue left an undefined carbonaceous dena except 
where the opening for the passage out of the vascular bundles 
existed, the scars of which are well seen from the inside. 
1 Quart. Jour. Geol. Soc., 1877, p. 213. 
2 Loc. vit., p. 218. 
