TRIBE MYTIIACEA. 233 



Section. A. 

 Having the general appearance of M. Modiolus' i.e. smooth and sub- 

 cuneiform. 



M. Modiolus.* Turton. Biv. 199. t. 15. f. 3. {young) — Gould 

 Mas 123. — Mytilus M. Lin. Sys. 12 ed. 1158. (certo).— Pen. 4. 

 23S.t. 69.— Don. t. 23.— Da. Cost.t. 15. /. 5.—D. p. 314.— W. 

 t. 12. f. 3\.—Mont. 163.— Mod. Vulgaris. F. p. 412.— M. Bar- 

 batus. Macg. Ab. 238. — Mytilus B. Mont. 11. {not Lin. certo). 

 Ovate oblong, ventricose, gradually widening anteriorly, cuticle of 

 an uniform yellowish or brownish chesnut or black, substance thick, 

 whitish with a darker or lighter tinge of livid purple ; hinge margin 

 ascending and straight for about half the length of the shell, um- 

 bonal ridge very distinct near the beaks which project and curve 

 outwards ; posterior extremity very short and narrow : anterior 

 edge never incurved. — Far. M. Papuana Lam. 1. — Bl. t. 64./. 3. 

 {good), Transversely produced, very narrow, posterior side much 

 attenuated. 6. N. Europe, N. America. The young are generally 

 bearded with filaments which do not spread at the base as in the true 

 Barbatus. The Gibbsii. of Turton s Bivalves {if this byssus be not ex- 

 traneous) may be distinguished by its filaments being serrated on one 

 edge 



M. Barbata. Lam. 14. — Philippi p. 70. — Mytilus B. Lin. 

 1156 certo. — Gualt. t. 91. H. mid. fig. Subtriangular, not at all 

 ventricose, under a concentrically imbricato-rugose ferruginous 

 cuticle, rich red covered with lanceolate barbations, whose edges are 

 not serrated except on the extreme posterior area, where the shell 

 is white ; dorsal edge rather short, forming an obtuse angle with the 

 much extended edge of the flattened anterior side ; posterior side 

 all but obsolete, the terminal beaks forming an acute angle with the 

 ventral margin : inside white stained with purplish red anteriorly : 

 ligament quite internal. 2 Mediterranean and N. Seas. Almost a 

 Mytilus, and very different from the young of M. Modiolus. This is 

 the true Barbatus ofLinnoeus as I have ascertained by comparison 

 with his specimens. 



M. Tulipa Lam. 2. Sow. G. — Reeve Sys. t. 101. f. 5. — Knorr. 

 ±.t. 15./. 3.— E. 221./. 1,-List. t. 759. f. 198. Oblong, thin, 

 inflated, under a yellow cuticle, which posteriorly becomes dark 

 chesnut, rayed with purplish red on the broader side ; hinge mar- 

 gin much elevated but short, the anterior dorsal line thence sloping 

 concavely to the obtuse anterior extremity ; ventral edge incurved 

 in the middle ; beaks touching : posterior end narrow but promi- 

 nent ; umbonal ridge not obtusely angulated. 2. America, IF. 

 Indies. Far. {!) from New Holland. Less elongated, the rays 

 united into one broad anterior streak, anterior edge uniting with the 

 ventral in an uninterrupted convex line 1|. The variety of La- 

 marck which I feel sure is a distinct species, is described from an exa~ 



