Nautilus pompilius L., in section, showing the Septa (s,s), the septal necks (s.n., s.n.), the siphuncle dotted in (si), and the large body chamber (ch).
Encyclopaedia londinensis, or, Universal dictionary of arts, sciences, and literature
London :Printed for the proprietor, by J. Adlard ..., sold at the Encyclopaedia Office ... by J. White ... and Champante and Whitrow ...,1810-1829.
biodiversitylibrary.org/page/15915147
Description: English: Despite the file name, this is Paracenoceras Spath, 1927 from the Matmor Formation (Middle Jurassic, Callovian) of Hamakhtesh Hagadol, southern Israel. Date: 16 July 2013, 20:03:13. Source: Own work. Author: Wilson44691.
Description: English: suture patterns of recent the nautilids Nautilus (top) and Aturia (bottom). Date: 28 November 2008. Source: Own work. Author: Antonov.