Monographie des Gastéropodes et des Céphalopodes de la Craie supérieure du Limhourg. By M. J. Binkhorst.
Twelve years ago M. Binkhorst took up the study of the superposition of the cretaceous beds of Limbourg, and of the special fauna which each contained. His first essay, 'Esquisse Géologique et Paléontologique des Couches crétacées du Limbourg et plus spécialement de la Craie tuffeau,' was published in 1859, and the subject was further completed by a communication to the Geological Society of France, in the November of that year. In his first researches he felt surprise, as many of us collectors have done in England, at the few species of Gasteropods compared with the representatives of other classes of marine animals. But he soon began to account for this seeming paucity. He knew that the few species cited were found in the friable beds worked in the quarries, and that others were found in the state of casts and moulds in the hard strata which traverse the Upper Chalk in the environs of Maestricht and Heerlen. Occupying himself then with assiduous researches for many years in these beds, he offers now in this Monograph of the Gasteropods of the Upper Chalk, no less than a hundred and six species belonging to thirty-eight genera. The species described in this excellent memoir, which is illustrated by six large and beautiful plates, containing 270 figures, are:—Rostellaria papilionacea, var., Goldf.; Rostellaria nuda, n. s.; Triton Koninckii, n. s.; Cancellaria obtusa, n. s.; Pyrula ambigua, n. s.; P. filamentosa, n. s.; P. tuberculosa, n. s.; P. planissima, n. s.; P. fusiformis, n. s.; Fusus Noeggerathi, n. s.; Fusus glaberrimus, Müll.; Buccinum supracretaceum, n. s.; Voluta deperdita, Goldf.; Voluta corrugata, n. s.; V. Debeyii, n. s.; Imbricaria Limburgensis, n. s.; Cypræa Deshayesii, n. s.; Natica patens, n. s.; N. ampla, n. s.; N. Royana, D'Orb.; N. fasciata, Goldf.; N. cretacea, Goldf.; N. spissilabrum, n. s.; Chemnitzia clathrata, n. s.; Cerithium tuberculatum, n. s.; C. tectiforme, n. s.; C. alternatum, n. s.; C. pliciferum, n. s.; C. maximum, n. s.; Nerinæa ultima, n. s.; Aporrhais Limburgensis, n.s.; Turritella quinquecincta, Goldf.; T. plana, n.s.; T. Omaliusi, Müll.; T.? sinistra, n.s.; T. nitidula, n. s.; T. conferta, n. s.; T. Falcoburgensis, n. s.; Vermetus clathratus, n. s.; Scalaria Haidingerii, n. s.; Solarium cordatum, n. s.; Xenophora onusta, n. s.; Nerita Montis Sancti Petri, n. s.; N. rugosa, Hœninghaus; N. parvula, n. s.; Turbo detritus, n. s.; T. bidentatus, n. s.; T. Strombeckii, n.s.; T. rimosus, n. s.; T. granose-cinctus, n. s.; T. clathratus, n. s.; T. rudis, n. s.; T. filogranus, n.s.; T. cariniferus, n.s.; Trochus Goldfussii, n.s.; T. Montis Sancti Petri, n. s.; T. lineatus, n. s.; T. sculptus, n. s.; Infundibulum Ciplyanum, De Ryckholt; Delphinula spinulosa, n.s.; Emarginula fissuroides, Bosquet; E. Muelleriana, Bosq.; E. supracretacea, De Ryck.; E. conica, n. s.; E. Dewalcquii, n. s.; E. radiata, n. s.; E. Hœvenii, n, s.; E. depressa, n. s.; E. clypeata, n. s.; Hipponyx (Capulus) Dunkerianus, Bosq.; Patella parmapharoidea, n. s.; Acmæa lævigata, n.s.; Siphonaria antiqua, n.s.; Dentalium Nystii, n.s.; Actæon granulato-lineatum, n. s.; Avellana gibba, n. s.; Avellana ventricosa, n. s.; Turbinella supracretacea, n. s.; T. plicata, n. s.; Cancellaria ? reticulata, n. s.; Pyrula nodifera, n.s.; P. parvula, n.s.; P. ? plicata, n.s.; Fusus lemniscatus, n.s.; F. squamosus, n. s.; F. formosus, n. s.; F. oblique-plicatus, n s.; Oliva ? prisca, n. s.; Mitra Waelii, n. s.; M. cancellata, Sowerby; Voluta monodonta, n. s.; Volvaria cretacea, n. s.; Natica prælonga, n. s.; N. Bronnii, n. s.; Cerithium novem-striatum, n. s.; Turritella Ciplyana, n. s.; Solarium Kunrædtense, n. s.; Turbo inflexus, n. s.; T. scalariformis, n. s.; T. Herklotsii, n. s.; T. granuloso-clathratus, n. s.; T. Zekellii, n. s.; Haleotis ? antiqua, n. s.; Emarginula Kappi, n. s.; Acteon cinctus, n. s.; Acteonella, sp.
All these, it will be seem, are new, except about a dozen described or quoted by Goldfuss, Hœninghaus, Bosquet, and De Ryckholt.
This fauna M. Binkhorst considers as belonging to the zone between high and low water in a littoral region of a subtropical ocean. Many of the genera which compose it are common to hot and to temperate seas, such as the Buccinum, Turbo, Emarginula, Scalaria, etc.; but others, such as the Voluta, Pyrula, Cancellaria, Solarium, Vermetus, Turbinella, etc., only inhabit the hot seas. The facies of the fauna indicates also, he thinks, the proximity of reefs of corals, great quantities of the debris of anthozoarians so fill many of the beds as almost to form them. It is probably to the high temperature of this epoch, he considers, that we owe the great species Voluta deperdita, Cerithium maximum, and those brilliant colours which many of the bivalves that he has found, have even in their ancient burial-place.
"Judging," he adds, "from the great number of fragment of casts and moulds belonging to species of which the determination and the description await the discovery of more perfect examples, those that we have described represent only a small portion of the mollusks of this class which were the contemporaries of the Mosasaurus."
He has also described a cephalopod, characteristic of the "marnes sans silex de Vaels," a score of species of cephalopods from the Upper Chalk, some of which are new, and among others many of the genus Ammonites, probably the last representatives of that important and numerous family, and one species of the Acanthoteuthis, D'Orb., which with the Acanthoteuthis prisca of Solenhofen are the only fossil species known to M. Binkhorst as described up to this time, and this the only one of the cretaceous rocks. In England however an Acanthoteuthis (A. antiquus) is recorded from the Oxfordian beds of Christian Malford and from Trowbridge in Wiltshire.
It is not a little singular however to find these remains of Gasteropoda occurring in the hard beds of the Limbourg district, in the form of casts and moulds, exactly as the remains of Gasteropoda do in those hard beds of the English white chalk to which Mr. Whitaker has lately given the name of Chalk-rock.
The great number of new species figured by M. Binkhorst should be an encouragement to the many British collectors of cretaceous fossils, to search well these hard beds for the Gasteropoda, of which in the form of casts they do, as we know personally by experience, contain great quantities.
In the beds of this hard chalk at Dover or Maidstone, a cubic foot of rock cannot be broken up without some casts of what appears to be an exquisitely sculptured Trochus being found. Dentalia also are common, and small (young?) Ammonites. We hope soon therefore to see M. Binckhorst's species matched by English examples, and some new forms added to them from our own famous chalk localities.