outer wall imperforate possibly rudimentary

knowledge base : exist
structure : number of wall ; outer wall
Number of walls : 2
Structure of outer carcass wall (OW/SW) : Carcass wall well defined
Structure of inner carcass wall (IW) : isn't included in the term
Carcass perforations: outer wall or single wall (OW/SW) : None
Carcass bumps: outer wall or single wall (OW/SW) : None
Carcass external plates: outer wall or single wall (OW/SW) : None
Stipules : isn't included in the term
Type of morphological tubes (OW/SW) : None
Additional sheath : isn't included in the term