CYPHOMA. 271 



marginata, Soic. striatula, Soic. 



nubeculata, Soiv. punctata, Duel. 



ovum, Linn. triticea. Lam. 



pyriformis, Sow. umbilicata, Soiv. 



Genus CALPURNUS, Montfort. 



Mantle-margin reflexed, simple, partly covering the 

 shell ; foot wide, expanded. 



Shell cypraeiform, dorsally gibbous, with a circular, de- 

 pressed line at each extremity, leaving a wart-like tuber- 

 cle ; aperture narrow, linear ; inner lip smooth, produced 

 posteriorly into a point as long as the hinder end of the 

 outer lip ; outer lip inflexed, dentato-lirate, the ridges 

 extending transversely. 



Syn. Cypraella, Swains. 



Ex. C. verrucosus, Linnceus, pi. 28, fig. 7. Shell, fig. 

 7, rt. 



The shell of Calpurnus is known at once by the pecu- 

 liar tubercle at each end ; it is a solid shell, longitudinally 

 striated ; a single species only is known. 



Genus CYPHOMA, Bolten. 



Shell oblong, ovate, with an obtuse, dorsal, transverse 

 ridge ; extremities rounded, not produced into elongated 

 beaks ; aperture nearly straight, almost central, contracted 

 behind, effuse in front ; inner lip smooth, simple ; outer 

 lip inflexed, the margin slightly crenate. 



8yn. Ultimus, Monif. Carinea, Swains. Binovo- 

 luta, Schl'dt. 



E.r. C. gibbosa, Linnaus, pi. 28, fig. 8. 



From the mark on the back of the shell and the po- 



