SQUALUS TRICUSPID•NS. From Brussels.
SQuALus VAccA. From Sicily.
SqUALUS PHISTODONTI:S. Very common.
SquALus LAMIA. Common in Malta, in Sicily, near Verona, at Brussels, Maestricht, Montpellier, Paris, and in England.
Snum.us AuotcuLATus. From Brussels.
PoisTon.urvs numus ? Some sharp teeth supposed to belong to the snout of the saw fish.
Teeth and spines of Rays. RAIA.
These are found in several places, and generally collect ed in great numbers. They are commonly adherent to the palate and tongue, as in the living animal. The species to which they belong are not ascertained, but the teeth themselves are arranged in certain divisions. M. Blainville makes four of these, but they are not intelligi ble without figures.
The spines of this genus are found in the same situa tions, but are neither so common nor so abundant.
The round teeth, or bufonites, vary in form, being large or small, hemispherical or flattened. The small hemisphe rical ones are the most common, and occur abundantly in Malta and Sicily. M. Blainville doubts if they belong to the anarrhychas above mentioned, or to a sparus, as some they are in some cases found in the rocky strata, in others in the alluvia.
have supposed; and is rather inclined to refer them to his new genus Palcobalistum.
But we must terminate this very unsatisfactory part of •ur subject, and pass on to another division of marine animals.
On :Ifarine Insects.
This division forms but a small one in the marine fossils, 'hough it is not easy to see why it should be so, as there is no subtance of this nature more durable than the shells of the larger crustaceous ones. But the smaller ones, from their tenderness, could scarcely be expected to occur at all, and indeed but few of these have been found. In the limestone of Pappenheim, one insect of this kind has been observed, without wings, yet bearing some resem blance to the winged tribes. It may possibly be a larva, and as this is a fresh-water formation, it is likely enough to have been such an one, similar to the complicated larva of the Libelltilx and some other insects. Were this as certained, it would rank properly with the division of ter restrial insects, among which so very small a number of species have been found.
The real nature of the Helmintholite is unknown ; but it has been supposed a marine lumbricus. Now this cannot be, if we arc right in considering the Oeningen strata, in which it occurs, as a fresh-water formation. The suppos ed specimens of the wings of butterflies which we have seen, have all appeared to be the scales of fish, or of tor toises, or the fragments of some very delicate shells re sembling that of our Argonauta argo. These latter occur in flint on the Devonshire coast.
The various specimens of the genus Cancer, (using the ancient genus,) are the most numerous of the marine fos sil Insects. Some crabs are found at Monte Bolca, with the fishes. Others occur in the London and Sheppey clay, and it is said that a fresh-water cancer, resembling the present river tray fish, is found in Anspach. None of the species of crabs have been found decidedly to resemble existing ones, and they are indeed frequently much muti lated; but it appears that about forty distinct kinds are known. Among other places they have been found in the Ea,,t Indies, in various parts, as also in Japan, and on the Coromandel coast. At Maestricht they are also abundant, and they occur in our chalk. It has been thought that a parasitic species similar to our Cancer Bernardus, is among those which occur at Maestricht.
Other aquatic, and probably marine insects, have also been occasionally found; but so obscure that conchologists have not been able to satisfy themselves respecting their real natures. The Dudley fossil, as it is commonly called, or the trilobites, is among the most remarkable of these ; but different species, apparently, of this genus occur, one of them in Derbyshire, and another in Carmarthenshire. It is imagined that five or six have been found. Some of these have been conceived to be analogous to the present genus Monoculus; but many opinions have been enter tained respecting its original nature. It appears safest at present to conclude, that it is an unknown crustaceous in sect. Together with the trilobites of Dudley, there have been found fragments of some other insects, equally ob scure, one of which, however, bears a general resemblance to an oniscus.