244 Mr. W. J. Sollas on the 



wise did in a note to the genus in their edition of the Anim. 

 s. Vert, of 1836. 



In 1842 Johnston* redescribed Fleming's specimen of Cy- 

 donium Miilleri, and, not recognizing the distinction between 

 Cydonium and Geodia, placed it in the 'latter genus with the 

 specific name zetlandica. 



In 1862 Bowerbank f reconstructed the genus Geodia, 

 taking as the basis for his characterization Geodia Barretti, 

 Bwk., which, as it happens, possesses the specially Lamarckian 

 character of numerous oscules congregated in a deeply de- 

 pressed area, though Bowerbank makes no mention of this 

 fact in his generic definition. Through this omission, and the 

 fact that G. Barretti, Bwk., is solid and not hollow within, there 

 is nothing in the character of Bowerbank's Geodia to distin- 

 guish it from Cydonium, if we choose to disregard, as we 

 must, the fictitious Alcyonian characters which Fleming erro- 

 neously added to his definition of Cydonium. 



In the same year (1862) Oscar Schmidt % also defined afresh 

 the Lamarckian genus Geodia, and, by leaving out the charac- 

 ters which Lamarck expressly stated were typical of his genus, 

 caused it to include the Cydonium of Fleming. Schmidt de- 

 scribed four new species, all of which appear to be true Cydo- 

 nia. He also described (p. 43 loc. cit.) a new genus of 

 Geodiido3 under the name of Caminus. It differs from Cydo- 

 nium (Geodia, Sdt.) in the absence of trifid spicules, and of a 

 needle-down covering the rind, and also by the presence of a 

 single large osculum. 



In 1864 Duchassaing de Fonbressin and Gio. Michelotti § 

 published a description with admirable illustrations of the type 

 species of Lamarck, Geodia gibberosa; they also described 

 and figured an allied species, Geodia cariboa, D. & M. 



In 1866 Bowerbank ||, having examined Fleming's type 

 specimens, enters into a long discussion respecting the con- 

 flicting claims of the names Cydonium and Geodia. I 

 quote his summing up : — " The history of this sponge (Geodia 

 zetlandica) presents a singular sequence of errors. In the 

 first place, Miiller is distinctly wrong in the designation of his 

 species, which undoubtedly is Alcyonium of Ray and Linnaeus. 

 Prof. Jameson, perhaps misled by the stellate mantlings on 

 the surface, believed the sponge from ' Fullah and Unsf to 

 be the same as Midler's specimen and an Alcyonium. Dr. 



* Hist, of Brit. Sponges, p. 195. 



t Phil. Trans, p. 1098. 



\ D. Spongien d. Adriat. Meeres, p. 49. 



§ Spongiaires de la Mer Caraibe, p. 104, pi. xxv. figs. 2, 8. 



|| Monograph Brit. Sponges, ii. p. 50. 



