TRIBE MYTIIACEA. 243 



M. Glandula. Totten in Sil. J. I. 26.^/1 3. — Gould Mass. f. 87 

 Obliquely rounded oval, rather inflated, brownish yellow, covered 

 with minute lines of growth crossed by minute and crowded radia- 

 ting lines, ligamenta! edge very short : beaks small and separate ; 

 within nacreous white: margin crenulated. ^%.. !• — ^* ^^ es ' 



M. Strigata. Nobis Zool. Pr. 1844. Small, oblong, fragile, 

 pellucid, moderately convex, pale green with chocolate ziczac 

 streaks, anterior side with radiating striae, posterior with a few lon- 

 gitudinal riblets ; anterior edge convex: no dorsal angle. i?*«^« 

 Philiqnnes. — Not unlike Discrepans in outline. 



M. Cicerula Moller Index Mol. Grcenl. — Mytilus Decus- 

 satus 1 Mont. — Brit. Mar. Conch, f. \.? Minute, subglobular, 

 thin, subcequilateral, greenish yellow, slightly roughened by a de- 

 cussation of minute radiating and concentric striae : margin finely 

 crenulated. ^. — Greenland. Longer than broad. 1 



MYTILUS. 



Longitudinal, equivalve : acute at the apex, affixed by a Byssus ; beaks 

 acute, nearly straight and terminal; hinge lateral, generally 

 without teeth : ligament marginal, and partly internal ; muscular 

 impression elongated, clavate and sublattral. 



* With radiating sulci. 



1 To this section belongs the Mytilus Decussatus of Montagu 

 which must be compared with the above species. 



See too, the M. Liturata of Menke's Synopsis, the Vitrea of 

 Moller (Moll. Graen), the Sinuosa of King (Z. J. 5.) the Cultellus 

 of Deshayes (Rev. Cuv. 1839) and the Chenui of Recluz (Rev. 

 Cuv. 1842.) which not being acquainted with, we are unable to put 

 into any of our sections. 



The shell from which the genus Mytilimeria of Conrad was 

 constituted, is evidently a new and distinct species. The situation 

 of the genus in the general system of nature, we know not ; its pre- 

 sent station being temporarily assigned to it, in accordance with 

 Mr. Conrad's statement, that it is allied to Mytilus and Modiola. 



MYTILIMERIA. 



Equivalve, suboval, thin ; beaks subspiral : hinge edentulous, with a 

 slight linear cavity under the beaks : muscular impressions two, ra- 

 ther small : palleal impression with a broad obtuse sinus. 



M. Nuttalii. Com. Jour. Philad. 7. p. 247. t. 19. /. 5. Sub- 

 oval, inflated, thin, fragile ; white with a very thin yellowish deci- 

 duous epidermis. 1. California in sponge* The single valves have 

 the appearance of Aplysice. 



r2 



