982 PELECYPODA. [Eularndlibranchiii. 



mantle largely free, more or less papillose ; the foot large, hatchet- 

 shaped, not byssiferous. 



Shell ovate, solid, porcellanous, microscopically radially lineated, 

 polished, smooth or concentrically waved, usually with a vivid colora- 

 tion and vernicose periostracum ; lunule definitely limited, unequally 

 divided, the right portion slightly larger, internal margins smooth ; 

 pallia! sinus ample, pointed in front ; left anterior and right posterior 

 dorsal margins grooved to receive the edge of the other valve ; the 

 anterior laterals and 3 cardinal teeth present in each valve, the right 

 posterior cardinal more or less distinctly grooved or bifid. 



Distribution. Warm and temperate seas. 



Fossil in the Tertiary. 



1. Macrocallista multistriata, Sowerby, 1851. Plate 62, figs. 3. '/. 



Cytherea (Callistu) nntltistrinta, Sow., Thes. Conch., ii, 1851, (528, pi. 136. 

 f. 177 ; ('hall. Rep., xiii, pt. 35, 134, pi. 1, f. 5 ; Button, P.L.S. N.S.W., 

 ix, 523. Callista multistriata, Deshayes, C.M.M., 71 ; M.N.Z.M.. 149. 

 Miretrix multistriata, Sowerby, Index, 8.9. Cytherea (Callista) planatella, 

 Lamarck, Grit. List, 44 ; Hutton, }. cle Conch., xxvi, 50 ; not of Lamarck. 

 Not Cytherea ntuItixtrintH, Romer, nor Dion? niultixtriuln. Reeve. 



Shell rather small, oval, acuminate posteriorly, moderately con- 

 vex, finely concentrically striated, solid, inequilateral, with pinkish- 

 brown radiate rays, polished. Beaks prominent, somewhat swollen, 

 acute, incurved and directed forwards, approximate, situate at the 

 anterior third. Anterior end short, narrowly convex, the dorsal 

 margin lightly concave and descending ; posterior end acuminate, 

 narrowly curved, the dorsal margin long, high, convex, descending ; 

 basal margin broadly rounded. Lunule moderately large, lanceolate, 

 the right portion slightly larger. Escutcheon usually defined by 

 pinkish-brown zigzag bands. Sculpture consisting of fine concentric- 

 striae, the intervening ridges resembling threadlike lirte ; the striae 

 continuous over the lunule. Epidermis thin, polished. Colour vari- 

 able, usually of a buff-colour, variegated with interrupted rays and 

 irregular wavy lines of a pinkish-brown tint, and frequently exhibiting 

 at intervals 2 or 3 bluish concentric zones. Interior white, dull, but 

 polished outside the pallia! line, with a large purple patch occupy- 

 ing the central and upper positions of the valves, sometimes reduced 

 to an oblique posterior radial ray. Margins smooth, rather blunt. 

 Hinge-plate not very large, lightly arcuate ; right valve with 3 cardinal 

 teeth, the anterior tooth fairly thick, vertical, separated by a narrow 

 groove from the second cardinal, which is a little thicker ; a triangular 

 free space separates the two teeth from the third cardinal, which 

 is long, narrow above, and broadened below, where it is distinctly 

 grooved ; the 2 anterior lateral teeth are small, horizontal, the lower 

 tooth longer and continued to the anterior cardinal ; left valve with 

 3 cardinals, the anterior thin, subvertical ; the second oblique and 

 stouter ; the two teeth connected above and forming a A-shaped 

 tooth ; the posterior cardinal long, close to and parallel with dorsal 



