In the snake the conus arteriosus is very much shortened and is not visible.
The conus arteriosus too begins to be divided into two chambers, and in Protopterus this division is complete.
conus arteriosus conus ar·te·ri·o·sus (är-tēr'ē-ō'səs)
A conical extension of the right ventricle in the heart, from which the pulmonary artery originates. Also called arterial cone, infundibulum.