88 
NATURAL HISTORY. (Fossils.) 
[north 
from the tertiary formation of Aix, in Provence; and, perhaps, also the 
Calamopleurus cylindricus, from the chalk of Brasil, which, having 
only slightly crenulated scales, appear to form a passage into 
The fourth Order, the Cycloid Fishes (so denominated from the 
orbicular or elliptic form of the scales, consisting of corneous layers, 
and having their posterior margin entire), is subdivided into the 
Acanthopterygian Cycloids , with the following families:—the Scom- 
beroids, Sphyraenoids, Labroids, Blennioids, Loplieoids ; and the 
Malacopterygian Cycloids, comprising the families of Cyprinoids, 
Cyprinodons, Esocids, Halecoids, and Anguilliform fishes. None of 
them have representatives in formations prior to the chalk. 
Among the most ancient of the family of Scomberoids, Cuv. ( Cases 
21, 2*2,) are the species of the genera Palceorhynchum, Palimphyes , 
Archceus , Isurus , and Anenchelum , in the slate of Glaris, of which 
a suite of characteristic specimens is here deposited; the chalk of 
Lewes has furnished instructive specimens exhibiting the dentition of 
Enchodus halocyon. Among those from Monte Bolca, the more promi¬ 
nent are the Thynnus propterygius , the Orcynus elongatus , the 
Carangopsis dorsalis, the Gasteronemus rhombus., Sac. ; the heads, &c., 
of a species of Cybium , from Sheppev, from which latter locality are 
also some species of Tetrapterus, a genus of the family of Xiphoids . 
( Case 23, middle shelves.) 
Of the family of Sphyrcenoids, (Case 23, middle,) the genera depo¬ 
sited are mostly known only bv portions of the jaws and teeth, which 
were formerly mistaken for bones of reptiles; such as those of the dif¬ 
ferent species of Saurocephalus described and figured in M. Agassiz’s 
great work, where also are to be found several delineations from speci¬ 
mens forming part of the series of Hypsodon Lewesiensis , which is now 
referred to a family distinct from the Sphyrsenoids, namely the Scombro - 
esocids of Muller. (Case 24, middle.) 
All species belonging to the family of the Cyprinoids or Carps, 
(Cases 24, 25,) are fresh-water fishes. The most interesting of those 
here deposited are the large and most perfect specimens of Tinea 
furcata and T. leptosoma, and another species, from the slate of Oenin- 
gen, which is also the locality from which one of the smaller species of 
Eeuciscus derives its name ; the largest species of the latter genus, 
L. Hartmanni, is from the tertiary formation of Steinheim, in Wiirtem- 
berg; the small L. papyraceus , from the lignite called paper coal, of 
Bonn and Bareuth, to which species also the impressions in semiopal, 
from Bohemia, appear to belong. 
Among the Esocids or pikes, (Cases 24 to 27,) the fine suite of 
specimens of Esox lepidotus from Oeningen, deserve particular notice, 
as likewise the large Sphenolepis squamosseus , from Aix, in Provence, 
and the Sphenolepis Cuvieri, of very rare occurrence in the gypsum 
of Montmartre, and named after its illustrious discoverer, by whom it 
was first noticed, in his Recherches sur les Ossemens fossiles. 
The Halecoids , (Cases 25 to 27, middle,) or Herrings, (a family con¬ 
sisting of Cuvier’s Clupese and Salmonidse, but which have lately 
undergone still further subdivision,) begin with the chalk, and 
are frequent in more recent formations: of those of the former 
may be mentioned the Clupea Scheuchzeri , megaptera, &c., from 
the slate of Glaris; and, above all, the considerable suite of spe- 
