27 
sandstones seemingly inexplicable on any other theory. As a general 
remark it may be added, that the middle carboniferous formations become 
less and less marine as they extend northward — the limestones of the south- 
west giving place to shales and coal seams, and thus showing a marked 
approach to the Scottish type aboA^e described. * 
Appendix. 
Specimens exhibited in illustration of the Paper. 
Ehizodus Hibberti, with large laniary tooth and part of jaw, about 5 inches 
long, when perfect at least 6 inches. 
Coprolites of Ehizodus. Burntisland. 
Megalichthys Hibberti. Scales, head-plates, jaws, and teeth. 
Palaeoniscus. Complete specimen, about 6 inches long. 
Eurynotus crenatus. Detached scales. 
Lepidodendron Sternbergii. 
Lepidostrobus comosus and ornatus. 
Sigillaria. 
Stigmaria ficoides. 
Sphenopteris affinis. 
Nautilus. Loanhead. 
Anthracomya (Unio). „ 
Cypris Scotoburdigalensis. Burdie House. 
Estheria Peachii. Arthur's Seat. 
The Megalichthys was not a fish of large size, as its name might lead one 
to suppose. The term was coined to designate a fossil now removed and 
established as a separate genus (Ehizodus). The teeth are of two sizes, as 
was the case with others among the sauroid ganoidians of that day; and 
the same is true of the Lepidosteus osseus, a living North American species. 
The enamelled part of the scale is divided from an unenamelled border by a 
deep furrow receiving a corresponding ridge on the adjoining scale. 
They are minutely pitted with here and there a larger and deeper 
Ehizodus Hibberti, formerly Holoptychius Hibberti. These genera have 
been thus distinguished by M'Coy. The species with large, thick, and 
* Since the above was read in January, a paper by Professor Hull, 
F.G-.S., in the "Geological Magazine" for February, 1871, shews that the 
same change may be traced in the carboniferous limestones of Ireland, the 
limestones of the south giving place in the north to shales, coal seams, and 
bands of ironstone. 
