88 
NATURAL HISTORY. (Fossils.) 
[north 
Among the specimens deposited to illustrate the first of those families 
(Cases 1 to 3, upper shelves), may be particularized some of the 
extraordinary types occurring only in the most ancient of the palaeozoic 
formations ; the old red sandstone of Scotland having furnished the 
most interesting of them, such as the Cephalaspis Lyellii, so named 
after its discoverer, by whom the specimen here deposited was presented, 
together with the equally remarkable Pterygotus * both from Carmilye 
quarries, Forfarshire ; — also various most instructive specimens of Coc- 
costeus and Pterychthys, such as these of Ccccosteus decipiens and 
cuspidatus from Caithness and Cromarty, and that of Coccosleus 
oblonyus from Lethenbar, presented by Major Cautley. 
Among the Acanthodians and Dipterians (Cases 4 and 5, upper 
shelves), both confined to the old red sandstone and carboniferous 
formation, may be pointed out : of the former family, the specimens of 
the fine species Cheirolepis called Cummingice, after the late Lady 
Gordon Cumming (presented by Sir Roderick Murchison); and of 
the latter, several species of Osteolepis , chiefly from Cromarty. 
Of the family of Lepidoids (Cases 1 to 6), divided into genera 
having invertebrated tails (homocerci) and those in which the vertebral 
column is prolongated into the upper lobe of the tail (heterocerci) : 
among the former are a suite of specimens of various species of Tetra - 
gonolepis of the lias, especially from Lyme Regis, such as T. speciosus , 
conjiuens , pustulatus , Leachii j those of Dapedius , especially of D. 
politus ; the several varieties of D. Colei from the same locality, and 
of D. Orbis from Barrow, the best specimens of which were presented 
by the late Countess of Aylesford ; the fine group of Semionotus 
Bergeri in lias, from the neighbourhood of Coburg; specimens of 
various species of Lepidotus, some of them gigantic, particularly 
the original specimens, figured by Agassiz, of X. Mantellii and X. 
Fittoni, from the Wealden of Sussex : the latter presented by 
P. J. Martin, Esq. ; X. Gig as, and other species from the oolite 
and lias of England and Wiirtemberg; — and, among those of the 
second division, the suite of species of Palceoniscus , chiefly from 
the Zechstein and magnesian limestone of Thuringia and England, 
the new red sandstone of Bohemia, & c. 
Among the most prominent species belonging to the different genera 
of the Sauroids, ( Cases 7 to 10), a family of which the remains occur 
both in the oldest and in recent formations, are those of Megalichthys , 
especially M. Hibberti, of which yet imperfectly understood fish some 
very instructive fragments are deposited, especially as illustrative 
of the nature of its teeth, formerly mistaken for those of Saurian rep- 
tiles ; also the several large species, not all equally well determined, of 
Sauropsis , chiefly from the lias of Wiirtemberg; and the Pygopterus 
Humboldtii, the largest species of which is from the copper-slate of 
Mansfeld: these genera belong to the heterocercal division of the 
family. Among the homocereals may be particularized a suite of spe- 
cies of Leptolepis, all of them from the beds of the oolitic limestone 
formation, and to some of which, in the lithographic stone of Sohlen- 
hofen, belong the vermicular bodies and impressions found in the same 
locality, and to which, though they appear to be Coprolites, the name 
* The Pterygotus is, however, now again referred to the Crustacea by M. 
Agassiz. 
