Two novel C(27)N(3)-type Lycopodium alkaloids, cryptadines A (1) and B (2) consisting of two octahydroquinoline rings (C(11)N) and a piperidine ring (C(5)N), have been isolated from the club moss Lycopodium cryptomerinum, and their structures and relative stereochemistry were elucidated on the basis of spectroscopic data, chemical transformations, and computational methods. Cryptadines A (1) and B (2) exhibited an inhibitory activity against acetylcholinesterase.