A probe (g) is introduced through this slit-like passage, and it is seen to pass out by the excurrent siphonal notch.
D, Excurrent siphonal notch of the mantle margin.
It is through this passage, or indirectly through the pores of the gill-plates, that the water introduced into the lower subpallial space must pass on its way to the excurrent siphonal notch.
Incurrent siphonal notch of the mantle margin.
Ac, Siphonal notch of the mouth of the shell.
H', Prolonged siphonal notch of the shell occupied by the siphon, or trough-like process of the mantle-skirt.
K, by the excurrent or superior siphonal notch of the mantle (fig.
The food of the Anodonta, as of other Lamellibranchs, consists of microscopic animal and vegetable organisms, brought to the mouth by the stream which sets into the sub-pallial chamber at the lower siphonal notch (e in fig.
Mytilus possesses no siphonal tube-like productions of the margin of the mantle-skirt, nor any notching of the same, representative of the siphons which are found in its fresh-water ally, the Dreissensia polymorpha.
A, Siphonal notch of the shell e, Everted buccal introvert (prooccupied by the siphonal boscis).