gr 
A516) 
Sp. 1. MODIOLA DISCREPANS. 
M. testa nigra; postice costis perpaucis, antice costis nu~ 
merosissimis, angustis, rotundatis, crenulatis, (sulcis sepe 
crenulatis exinde cancellatis) ; latere antico medium ver- 
sus late sinuato. 
Mytilus discrepans. Mont. Test. Brit. 1, 169—Supl. p. 65, 
t. 20, f..A.. 
Fleming, Edin. Enc. art. Conchology. 
Habitat in mari Scotico. : 
DISCORDANT MODIOLE. 
Shell black ; hinder part with a few ribs, anterior part with 
a vast number of narrow, rounded crenulated ribs, (with 
the interstices often wrinkled so, as to produce a cancel- 
lated structure) ; anterior side, towards the middle, broadly 
sinuated. 
This species is very common in the Scottish sea, and in 
the Frith of Forth is often found of one inch and a quarter 
in length. Montagu says, that small specimens are com- 
mon on the Devonshire coasts. When young, it is often 
Juteous or greenish ; when old, it is always black, with 
decorticated beaks. 
## a 
Se. 1. MODIOLA INCURVATA. 
Taz. LXXII. Fie. Il. 
M. testa olivaceo-virens, subiridescens ; latere antieo lu- 
tescente late et profunde emarginato. 
Fjabitat 
foetal 
