Pvn H,i I'UitlS

114 mytilidjE.
scription agrees
ad amussim with trie common shell which
is usually regarded as M. modiolus, the animal of which
he says is eaten in Norway. According to Lamarck, his
Modiola tulipa inhabits " les mers d'Amerique." Our
shell is the Modiola vulgaris of Fleming. The young is
the Mytilus curtus of Pennant and the Modiola barbata
of Macgillivray.
3. M. barba'tus #j Linne.
M. barbatv.s, Linn. Syst. Nat. p. 1156. Modiola barbata, F. & H. ii. p. 190,
pi.
xliv. f. 4.
Body reddish-brown : mantle not folded :
coarsely pectinated ;
the upper ones.
gills narrow,
lower pair more than twice the depth of
Shell irregularly triangular, pointed at the smaller end and
expanding obliquely outward to a broad and obtusely rounded
edge in front, compressed, but gibbous towards the beaks, solid,
somewhat glossy on the upper part, but elsewhere of a dull
hue owing to the close investment of the bearded epidermis :
sculpture, numerous concentric membranaceous ridges
: colour
yellowish-red, or scarlet: epidermis thick, yellowish-brown,
minutely but deeply striated lengthwise, thickly foliated, and
rising on the posterior side and in front into a fringe of thorn -
like projections, which are distinctly serrated or barbed on the
the epidermis is reflected over
side facing the ventral portion ;
the front edge and forms a glistening band inside it : margins
thick, straight or incurved on the ventral side, angulated
behind, and obtusely rounded in front : byssal sinus large and
rather : long beaks small, close together, incurved, placed (as
in M. edulis) very near the point of the shell: hinge-liiie
straight, occupying about one-half of the dorsal margin : liga-
ment narrow, much sunk: hinge-plate thick, deeply grooved
for the reception of the ligament : hinge toothless,
reflected :
inside highly nacreous and iridescent, sometimes beautifully
stained with purple on the posterior side and occasionally
studded with sessile pearls : muscidar scars indistinct : pallia!
scar well defined. L. 1*8. B. 1.
Yar. oblonga. Shell more elongated and tumid ; ventral
* Bearded.