Pvn H,i I'UitlS

118 MYTILID.E.
gas generated in the process of decay. The thin texture
of the shell, the coloured rays, and the greater distance
of the beaks from the anterior margin will readily serve
to distinguish this species from the young of M. modio-
lus. It differs from M. barbatus in its rhomboidal
shape, in being much more convex, and its paler colour,
as well as in the rays, position of the beaks, sculpture,
and epidermis.
M. Adriaticus appears to have been known to Montagu
; for in his account of M. barbatus he says, " A
variety is faintly radiated." The Modiola tulipa of
Lamarck (for which the British species has been mis-
taken) is described as a native of the American seas,
and a variety of it as coming from New Holland. The
tropical shell is of a different shape
and substance from
ours, and they only agree in the style of colouring.
Lamarck pointed out the distinction between them.
The present species may be the Mytilus pictus of Gmelin
(from Bonanni),
which is said to inhabit the coasts of
Spain ; but the diagnosis given by him is too slight for
the purpose of identification, and the Modiola picta of
Lamarck is another species and better known. In
Thorpe's f
'
Marine Conchology
our shell has the appropriate
name of " radiata" which appears to have been
given to it by the late Captain Brown.
5. M. phaseoli'nus *, Philippi.
Modiola phaseolina, Phil. Moll. Sic. ii. p. 51, tab. xv. f. 14; F. & H.ii.
p. 186, pi.
xliv. f. 3.
Body reddish-brown :
strong, light horncolour.
foot long and cylindrical :
byssm-
Shell conformable with its name, obliquely expanding from
* Shaped like a kidney-bean.