_ GINGLYMACONCHA. PINNADZ. 3a0 
** Shell with longitudinal and oblique grooves. 
3. Mopiouta PRIDEAUXIANA. 
Shells with their valves cancellated behind; the anterior 
side towards the middle broadly sinuated ; the hinder side with 
a rounded wing. 
Modiola Prideauxiana, Leach, Zool. Miscel. ii. 85. 
This beautiful little shell, which does not exceed a quarter 
of an inch in length, was discovered by my kind and worthy 
friend and cousin Charles Prideaux, Esq. of Kingsbridge. Se- 
veral specimens were found by him amongst some sand from 
Milton in the southern coast of Devon, which I name after 
him, as a just tribute due to one of the most active and zealous 
investigators of the marine zoology of Britain. 
** Shell grooved behind and sometimes before. 
4. MopIoOLA DISCREPANS. 
Shells oblong, oval, thin; their valves covered with a pale- 
green, olive or black epidermis ; under the epidermis pink, in- 
ternally whitish ; the valves behind with very few, before with 
very numerous, narrow, rounded, wrinkled ribs, thence appear- 
ing to be cancellated. Length one inch and a half; height 
seven-eighths of an inch. 
Mytilus discrepans, Da Costa, Brit. Conch. 221. t. xvii. f.1; 
Mont. Test. Brit. 169; Leach, Zool. Miscel.ii. 36; Flem. 
Edinb. Encycl. vii. 99 ; Dill. Dese. Cat. 319; Turt. Conch. 
Diet: 112. 
Mytilus discors, 3., M. §& R. Trans. Linn. Soc. viii. 111. 
Inhabits the European and Mediterranean seas on sandy 
bottoms, adhering to the roots of Fuci and other marine plants, 
and sometimes to oysters. 
This species is common in the Scottish seas, and in the Frith 
ot Forth; it is often found on the Devonshire coasts: Col. 
Montague only found young specimens, but Mr. Cranch found 
them in the Plymouth Sound. Young specimens are always 
luteous or green ; when nearly full-grown, green or olive-green : 
