108 
MYTILUS. MUSSEL . 
Mr. Wood observes, that as this species seems to con¬ 
nect the Myce with the Solenes, it is more properly placed 
at the end of the genus. 
An imperfect specimen of this extremely rare shell was 
thrown up on the beach, at Teignmouth in Devonshire, in 
the summer of 1817- v. m. 
MYTILUS. MUSSEL. 
Shell with two valves, generally fixed by a beard 
of silky filaments : hinge without teeth, hut marked 
by a longitudinal groove which is sometimes finely 
notched. 
* 1. Mytilus Hirundo. Swallow-tail Mussel. Fig. 7- 
Lister, pL 220. f. 55, and pi. 224. f. 59— Bar but, pi. 11, 
f. 8. 
Shell flat, with two unequal lobes reaching obliquely on 
each side from the hinge ; the posterior lobe smaller, 
somewhat triangular and ending in a point, and irregularly 
wrinkled longitudinally ; the anterior lobe as long as the 
shell, transversely wrinkled towards the end, which is ra¬ 
ther rounded, and at its junction with the shell marked 
with semicircular wrinkles: color glpssy chesnut-biwn 
with, whitish longitudinal rays or stripes, deeper brown 
towards the margin, which is rounded and strongly wrin¬ 
kled transversely ; Inside silvery white: hinge a very lon» 
straight groove, in consequence of the great extension of 
one of the Jobes, and a, minute obtuse tooth-like projection 
within opposite the beak, which is rather tumid and pointed 
but not extending beyond the margin: length five eighths of 
an inch; breadth nearly an inch, including the wings or 
lobes, which run parallel with each other in an oblique di¬ 
rection. 
This very interesting addition to the British Conchology, 
we found on the sand bank between the Pigeon-house and 
' the light-house, in Dublin bay, in the summer of 1815. 
m. 
2. Mytilus Morio. Black Mussel. 
Avicula Morio. Leach, Zool . Miscell. pi. 38. f. 2. 
Shell resembling M* Hirundo in shape, but is of a black 
color 
