A Monograph of the Trilobites of North America: with Coloured Models of the Species - Jacob Green

Body contractile.

Buckler oculiferous and not lobate.

Abdomen trilobate, with 8 articulations.

Tail, costal arches covered, middle lobe naked.

The Asaphus expansus of Dalman, and several other known species may be arranged under this genus.

As Count Rasoumowsky has given no specific appellation to the fossil above alluded to, we propose to call it after his own name, Hemicrupturus Rasoumowskii. We examined the fine specimen from which our cast is taken in the cabinet of the Baltimore College, and for this favour we are indebted to the kindness of Dr. J. J. Cohen, one of the Professors in that rising institution.

The following list includes all the genera and species of the Trilobite Family, hitherto described as far as known to the author. It is taken from De La Beche's Manual of Geology.

NAMES.		AUTHORS.	LOCALITIES.
Calymene	Blumenbachii,	Al. Brong.	Europe—U. States.
	Macrophthalma,	do.	Europe—U. States.
	Variolaris,	do.	Europe.
	Tristani,	do.	Europe—U. States.
	Bellatula,	Dalman.	Europe.
	Ornata,	do.	Europe.
	Verrucosa,	do.	Europe.
	Polytoma,	Dalman.	Europe.
	Artinura,	do.	Europe.
	Sclerops,	do.	Europe.
	Schlotheimi,	Brown.	Europe.
	Latiferus,	do.	Europe.
Asaphus	Cornigerus,	Al. Brong.	Europe.
	Caudatus,	do.	Europe—U. States.
	Hausmanni,	do.	Europe—U. States.
	De Buchii,	do.	Europe.
	Brongniartii,	Deslongchamps.	Europe.
	Extenuatus,	Wahlenberg.	Europe.
	Granulatus,	do.	Europe.
	Expansus,	do.	Europe.
	Crassicauda,	do.	Europe.
	Angustifrons,	do.	Europe.
	Heros,	Dalman,	Europe.
	Platynotus,	do.	Europe.
	Frontalis,	do.	Europe.
	Læviceps,	do.	Europe.
	Palpebrosus,	do.	Europe.
	Sluzeri,	do.	Europe.
Ogygia	Guettardii,	Al. Brong.	Europe.
	Desmaresti,	do.	Europe.
	Wahlenbergii,	do.	Europe.
	Sillimani,	do.	Europe—U. States.
Paradoxides	Tessini,	do.	Europe.
	Spinulosus,	do.	Europe.
	Gibbosus,	do.	Europe.
	Scaraboides,	do.	Europe.
	Hoffii,	Goldfuss.	Europe.
Nileus	Armadillo,	Dalman.	Europe.
Nileus	Glornerinus,	do.	Europe.
Illænus	Centaurus,	Dalman.	Europe.
	Centrotus,	do.	Europe.
	Laticauda,	Wahlenberg.	Europe—U. States.
Ampyx	Nasutus,	Dalman.	Europe.
Olenus	Bucephalus,	Wahlenberg.	Europe.
Agnostus	Pisciformis,	Al. Brong.	Europe.
Isotelus	Gigas,	De Kay.	United States.
Isotelus	Planus,	do.	United States.
Genera and Species not fully determined.
Trilobites	Cephaleurya,	Rafinesque,	United States.
	Simla,	do.	United States.
	Granulata,	do.	United States.
Bilobites	Lunulata,	do.	United States.
Bilobites	Lobata,	do.	United States.

From the short descriptions given by Professor Rafinesque of the five last mentioned fossils, I conclude that they belong to the genus Calymene of Brongniart.

The study of the trilobites naturally leads to the consideration of those beings which appear to have inhabited our earth previous to the creation of man. Every one knows that the sceptical naturalist has drawn from these vestiges of organic life, an argument contradictory to the Mosaic account of the history of the world, and though every cavil of the least importance, urged against the truth of the sacred historian, has been triumphantly confuted, still, the geological sciolist boldly impugns his veracity, whenever any new facts in his science can be distorted to his purpose. Such being the case, we cannot conclude this preface without briefly stating two or three methods by which any seeming discrepancies may be explained. First, those who imagine that the six periods of creation, mentioned in the beginning of the pentateuch, mean literally days of 24 hours each, believe that, as only a small part of the earth was at first required for the abode of man and the higher animals, the present continents might have remained as long beneath the waters, and have undergone every change necessary to solve this geological puzzle.

Genera and Species not fully determined.