544 
SILUKIA. 
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-lime- 
stone of that Arctic tract. This formation, surmounted by Triassic and Jurassic 
rocks, reposes on unfossiliferous red and green ferruginous slates and conglo- 
merates, which lie upon clay-slates, quartzites, and limestones, also devoid of 
fossils, and these rest on vertical strata of micaceous and hornblendic slates with 
bands of quartzite, crystalline 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 Silurian, but also the representative 
of the Laurentian rocks. 
L. — Conodonts of Pander (pp. 134 & 356). 
u On the Lower Silurian organisms called 1 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 hooklets of Oephalopods, 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 structure of the hooklet 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 hooklet 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. 
u The more minute hooklets 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 hooklets 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, horny teeth of Myxinoids and Lampreys ; and the absence of any other 
hard part in the strata containing the Conodonts tallies with the condition of 
* ' Monographic der fossilen Fische (Untor-Silurisehe Fische, Conodonten),' 4to, 1856. 
