References
- 1821 . Nova Acta Reg. Soc. Scient Upsaliensis , viii : 86 – 86 .
- This is of course no uncommon thing. Barrande gives numerous figures of Endoceras and Orthoceras into whose siphuncles young or smaller shells belonging to those genera have been introduced after the death of the animal and the partial destruction of its shell. (See Syst. Sil. de la Bohême ii xxxviii xxxviii figs. 9, 11; also Pal. of New York, by James Hall, vol. i, 1847, pl. xlviii. fig. 3.)
- 1837 . Lethæa Svecica , : 28 – 28 .
- Dec. 1881 . Bull. American Mus. Nat. Hist. no. 1 Dec. , 20 – 20 . New York 23
- See a valuable paper by Prof. F. Schmidt, of St. Petersburg On the Silurian (and Cambrian) Strata of the Baltic Provinces of Russia, as compared with those of Scandinavia and the British Isles Quart. Journ. Geol. Soc. 1882 xxxviii 514 514 inalso J. E. Marr, ‘On the Classification of the Cambrian and Silurian Rocks,’ pp. 74 and 82 (1883)