tes biplex Sowerby, 1821 
_ Ammon 
CEPHALOPODA Ammonites biplex 
Sowerby, 1821. 
1821. — SoWERBy (James). The Mineral Conchology of great Britain, 
HAN p' 168: 
Type specimen. 
[Sowerbv Collection, at the British Museum]. 
1e 
T. — Ammonites biplex, side view, nat. size. 
T.f — The same, natural cross-section, nat. size. 
PALAEONTOLOGIA UNIVERSALIS. — 58° 
