Brachiopod Homœomorphy

Abstract

To be able to arrange, in the Geological Department of the British Museum (Natural History), the species known as Terebratula diphya and T. diphyoides , with their allies, it was necessary to ascertain the generic and specific names which such shells should bear. The following remarks are partly the results of such enquiries, partly of investigations carried on at other times in connexion with other collections. The work has led to finding certain overlooked specific designations, while there seem to be disclosed not only notable cases of homœomorphy, but an interesting course of Brachiopod evolution. To deal with the specific synonymy:—The name diphya , Colonna, is pre-Linnean, and therefore cannot remain. The first post-Linnean designation for some of the shells in question is given by Bruguière in 1792 [3]. He named and figured a non-perforate shell Terebratula pileus (p. 424), and a perforate one T. cor (p. 425) These figures, with others of Terebratulæ were reproduced in the ‘Encyclopédie Méthodique’ [4], being drawn under Bruguière's direction, as he states in the ‘Journal d’Histoire Naturelle’ p. 419. They were published in 1797 [33], without any names, and were accompanied by figures of another perforate diphya -like fossil. In 1819, Valenciennes [36] wrote the articles on the Terebratulæ in Lamarck's ‘Animaux sans Vertèbres’: he named the last-mentioned fossil (Ency. Méth. pl. ccxl, fig. 4) Terebratula deltoidea ; to the reproduced figures of Bruguière's T. pileus (Ency. Méth. pl. ccxli, fig. 1) he gave the name T. triangulus ; and the reproduced figures of Bruguiére's T. cor he