All that pertains to the science of Palæontology is of consequence to the geological inquirer; therefore a few notes and illustrations relative to the Brachiopoda may, perhaps, prove acceptable to the general reader, and, at the same time, stimulate some others to prosecute an inquiry upon which so much time and labour have been already expended.

It was justly observed by a distinguished naturalist, that there exists a decided advantage in the same subject being investigated by a number of different observers; and the truth of this statement has been fully substantiated by the information already acquired on all that concerns the affinities, classification, and anatomical structure of the Brachiopoda. But it must also be remembered, that, although these topics may have been individually and collectively the subject of considerable investigation, much still remains to be discovered and satisfactorily explained before many of the problems relating to the character and history of the class can be considered as finally determined.

All palæontologists seem to agree that the Brachiopoda should bo divided into two principal groups. The first will include all those genera and species which have their valves articulated by means of teeth and sockets; the second will comprise those forms which, being un-articulated, have their valves kept in place by means of muscular and other contrivances.