544                                                  SILUEIA.

stantiates the fact that, although fragments of rock with true Permian fossils
have been found in detached blocks on the adjacent ^Thousand Islands,' the
fossils described by M. de Koninck are not, as was supposed, of Permian age,
but are true Carboniferous species which abound largely in the Mountain-Ume-
stone of that Arctic tract. This formation, sm-mounted by Triassic and Jurassic
rocks, reposes on unfossUiferous red and green ferruginous slates and conglo¬
merates, which Ue upon clay-slates, quartzites, and hmestones, also devoid of
fossils, and these rest on vertical strata of micaceous and hornblendic slates with
bands of quartzite, crystaUine limestone, and dolomite. Now, as all this great
series is based upon gneiss and granite, we may not unreasonably infer that
Spitzbergen in itself may be found to contain not only, as the author suggests,
the equivalents in time of the Devonian and Silmian, but also the representative
of the Laurentian rocks.
 

L.—Conodonts of Pander (pp. 134 & 356).

" On the Loiver Silurian organisms called ' Conodonts^ by Dr. C. H. Pander*.—
Minute, glistening, slender, conical bodies, hollow at the base, pointed at the end,
more or less bent, with sharp opposite margins, might well be lingual teeth of
Gasteropods, acetabular booklets of Cephalopods, or teeth of Cartilaginous
Fishes.

" Against the latter determination is the minute size of the bodies called ' Co¬
nodonts ' by Dr. C. H. Pander. Their basal cavity doubtless contained a forma¬
tive pulp; but the proof that the product of such pulp was ' dentine' is wanting:
the observed structm'e of the booklet presents concentric conical lamellae of a
dense structureless substance containing minute nuclei or cells.

^^ In some specimens the base is abruptly produced, and divided from the body
of the booklet by a constriction,—a form unknown to me in the teeth of any
Fishes, but presented by certain lingual teeth of Gasteropods, e. g. the lateral
teeth of Sparella. In other Conodonts the elongated base is denticulate or ser¬
rate, as in the lateral teeth of Buccinum and Chrysodomus. It is improbable,
however, that they belong to any conchiferous toothed mollusk, the shells of
such being wanting in the deposit where the Conodonts are most abundant.

'^ The more minute booklets have a yellowish transparent horny appearance ;
the larger, perhaps older ones, present a harder whitish appearance. Their
analysis by Pander yielded ^ carbonate of lime,'—carbonic acid being evolved
by the application of dilute nitric acid, and oxalic acid producing an obvious
precipitate.

"■ The detached condition of the booklets and the integrity of the thin border
of the basal pulp-cavity indicate that they have not been broken away from any
of those kinds of attachment to a bone which the minute villiform teeth of
osseous fishes would show signs of The Conodonts have been supported upon
a soft substance, such as the skin of a Mollusk or Worm, the mucous membrane
of a mouth, or throat, or proboscis : but, to select the teeth of Cyclostomous or
Plagiostomous Fishes as the exclusive illustration of the above condition, is to
take a partial and limited view of the subject.

'' In comparing the Conodonts with the teeth of Fishes, they present, as Dr.
Pander recognizes, the closest resemblance, in that class, with the conical,
pointed, homy teeth of Myxinoids and Lampreys; and the absence of any other
hard part in the strata containing the Conodonts tallies with the condition of

* ' Monographie der fossilen Fische (Unter-Silurische Fisehe, Conodonten),' 4to, 1856.