190 MYTILID^. 



M. barbata, Linnseus. 



Mussel-shaped, subarcuated, and somewhat lobed below ; epi- 

 dermidal byssus serrated at the edge ; surface with concentric 

 wrinkles ; dorsal angle much raised ; beaks quite terminal. 



Plate XLIV. fig. 4. 



Mytiluslarbatus, Linn. Syst. Nat. ed. 12, p. 1156 (from type). — Poli, Test. 



Sicil. vol. ii. p. 210, pi. 32, f. 6, 7. 

 Modiola Gibbsii, Leach, Zoolog. Miscellany, vol. ii. p. 34, pi. 72, f. 2. — Turt. 



Dithyra Brit. p. 200. — Fleming, Brit. Anim. p. 413. — 



Brit. Marine Conch, p. 107. — Brown, 111. Conch. G. B. 



p. 78, pi. 27, f. 7. 

 „ barbata, Lamarck, Anim. s. Vert. (ed. Desh.) vol. vii. p. 22. — 



Philifpi, Moll. Sicil. vol. i. p. 70, and vol. ii. p. 50. — 



Hanl. Recent Shells, vol. i. p. 233. 



This rough-looking- shell is, from its great attenuation in 

 front, of a subtriangular figure, and often subarcuated ; the 

 beaks being absolutely terminal, there is no appearance of 

 any anterior side beyond them. The valves, which are 

 opaque and moderately strong, are decidedly compressed, 

 except at the umbonal region ; the diagonal elevation is 

 broad, and not at all carinated ; the portion which precedes 

 it is remarkably small and narrow. Beneath the glossy ful- 

 vous epidermis which veils the external surface the shell is 

 white, or stained upon the posterior triangle with scarlet or 

 rose-colour ; almost the entire exterior is, however, concealed 

 by a most closely-disposed shaggy beard, whose terminal 

 filaments are finely but distinctly serrated on that edge 

 which looks towards the ventral margin. The appressed 

 and broadly triangular bases of these processes (frequently 

 in the case of dead specimens the only vestige of the byssal 

 garment) are arranged in concentric lines, inducing regular 

 crowded and often coarse wrinkles upon the epidermis. 

 The hinder dorsal edge, which is greatly elevated, forms a 



