CHAPTER XII. 
THE MUSSEL — MYTILID2E. 
“ Ecce inter virides jactatur mytilus algas.” 
Anlhologia. 
This family of Acephalous Molluscs includes the Sea Mussel, Mytilus ; 
the Pond Mussel, Anodonta ; the Painter’s Mussel, or Mulete, Pina 
indium ; and some others, in which the mantle is open before, 
Fig. 14V. Mytilus edulus (Linnaeus). 
' Vl tii a distinct and separate opening for the issue of the residue of 
'Tgestion ; also a foot, which assists the animal to creep, or at least to 
draw itself forward, to guide it, and to attach itself by the byssus. 
The well-known shell of the mussel (Eig. 147, Mytilus edulus ) is 
T^gitudinal, equi valve, and regular, pointed at the base, with capa- 
<% to attach itself by a byssus ; the hinge has no teeth, but a deep 
jhrrow, in which the ligament is located. In the genus Mytilus the 
yssus is divided to its base. In Modiola it has a common corneous 
Ce utre. In Pina the anus is furnished with a long angular base. In 
al1 these genera the foot is small, its retractile muscles numerous, and 
