./. Starkie Gardner — On the Gault Aporrhaidce, 201 



scribed a Blackdown specimen, and also, p. 108, one from the Grey- 

 Chalk. He says : " This species occurs in the Greensand of Devon- 

 shire, and is figured in the third volume of Organic Eemains. As it 

 has not received a specific appellation, I have named it from my 

 excellent friend James Parkinson. Esq., M.G.S." It is therefore 

 evident that, although he confounded the Greensand with the Chalk 

 species, the Blackdown specimen figured by Parkinson he intended 

 to bear the name Parkinsoni. The figures in pi. xviii. are unfortu- 

 nately of not much value. 



This error of Mantell has led to much misunderstanding and 

 confusion. 



In 1827 Sowerby, in the Mineral Conchology, pi. 558, figs. 5 and 6, 

 re-figured Parkinson's original examples from Blackdown, but unfor- 

 tunately included under the same name a quite distinct London-clay 

 species, now known as A. Sowerbii. He again figured the Black- 

 down fossil for Fitton in the Geol. Trans. 2nd series, vol. iv. pi. 

 xxviii. In 1839 Geinitz, in his work on the Saxon and Bohemian 

 Cretaceous Series, figures some imperfect and doubtful specimens as 

 B. Parkinsoni, but considers that Mantell had figured a different 

 species from Sowerby. The figure that most resembles Parkinsoni, 

 and which he calls Parkinsoni of Sowerby, he re-named Beussii, 

 distinguishing it as having " wider and shorter whorls, with the ribs 

 multiplied on the last whorl, and continued to the outer edge of the 

 wing." Geinitz, however, subsequently, in 1850, declared that Par- 

 kinsoni is not found in Germany, all the various forms there being 

 distinct. Goldfuss figures a very similar form as B. papilionacea, 

 Reuss, two others as B. Beussii and B. megaloptera (Verst. der 

 Bohm. Kriede, tab. ix). 



The following notices probably all refer to true Parkinsoni. 

 Brongniart, 1829 ; Leymerie, 1842, Gault, not Lower Chalk ; D'Archiac 

 and Lesueur, 1846, figuring at the same time what appears to be 

 a young specimen of this shell as Littorina plicatilis, Mem. Soc. 

 Geol., vol. v. pi. 17. f. 8; Graves, Gault of Oise, 1874; D'Archiac, 

 Gault of Escragnolles, Cornuel, Haute-Marne, 1 851 ; Gras, from Isere, 

 1852 ; Kenevier, Perte-du-Rhone, 1854 ; Cotteau, from the Yonne, 

 1854 ; Ebray, Lower Gault of Cosne, 1857 ; Baulin and Leymerie, 

 Yonne, 1858 ; and Saamann from the Glauconie de la Sarthe. In 

 addition to these, this shell is figured by Pictet and Boux in the 

 Moll. Foss. des Gres Verts, pi. 24, f. 25 ; and by Briart and Cornet, 

 Meule-de-Bracquegnies p. 18, pi. ii. f. 4, 5, 6 ; fig. 4 has a wing 

 differing from ours, but it has probably been restored ; Dr. Chenu 

 in the Man. Conch, p. 560, 1859. D'Orbigny figured A. marginata 

 in the Terr. Cret. as A. Parkinsoni, and mentions it in the Prodrome, 

 in which he separates the Blackdown species under the name of B. 

 Mego3ra. 



In England, Professor Edw. Forbes was, I think, the first to 

 separate the Chalk species of Mantell from that of the Gault, in the. 

 Quart. Journ. G. S. for 1845, p. 350 ; Prof. Morx-is gives it in his 

 Catalogue of British Fossils from Folkestone and Blackdown ; and Mr. 

 Tate described it under a sub-generic name as Perissoptera Beussii in 



