Observations on the purposes of the embryonic sheaths of Endoceras, and their bearing on the origin of the siphon in the Orthocerata. Bulletin of the AMNH ; v. 1, article 3.

Whitfield, Robert Parr, 1828-1910.2006-02-142006-02-141881http://hdl.handle.net/2246/1687p. 20-28 : ill. ; 24 cm.Includes bibliographical references.84943659 bytesapplication/pdfen-USQH1 .A4 vol.1, art.3, 1881Endoceratoidea.Orthocerida.Cephalopoda, Fossil.Observations on the purposes of the embryonic sheaths of Endoceras, and their bearing on the origin of the siphon in the Orthocerata. Bulletin of the AMNH ; v. 1, article 3.text