M'CULIDA. 145 



eighths of an inch in breadth. There is a most minute radiating 

 sculpture which produces the peculiar shagreen. I do not thiuk 

 Leach ever published the species. 



69. L. lucida, Loven, f. 23, 24, 25. — T. perparva, ovalis vel 

 subovata, subaequilateralis, subventricosa, sublaevigata, postice 

 striis pertenuibus lougitudinaliter sculpta, cute polita cinereo- 

 rlavescente induta. Extremitas postica superue eminentior et 

 oblique subrectangularis. Margo dorsalis amicus convexus, de- 

 clivis; posticus vix declivis, demum subretusus. Nates neque 

 prominentes nee acutae. Area; dorsales baud definite. — Very 

 small, oval or subovate, subventricose, scarcely, if at all, gaping 

 at either end, without umbonal ridge or indented ray, clothed with 

 an iridescent, polished, ashy-yellow epidermis, smooth to the eye, 

 but under a lens seen to be graven posteriorly with concentric or 

 longitudinal scratches, which are distant below, finer and closer 

 above. Extremity of the slightly shorter anterior side rather 

 attenuatedly rounded : posterior end obliquely subrectangular 

 above, its tip much above the middle ; lower posterior edge con- 

 vex, and more frequently oblique. Front dorsal slope moderate, 

 convex or subarcuated : hinder dorsal slope very slight, plano- 

 convex, subretuse at the extremity. Ventral margin convex in 

 the middle, arching upwards at both ends. Dorsal areas wholly 

 undefined, the surface of the hinder one a little flattened. Teeth 

 rather, and nearly equally, numerous on either side of the very 

 minute and shelving cartilage-pit. — In the oval form, the hinder 

 extremity is at times subbiangular, the lower corner being, however, 

 rounded off. 



70. L. pygm^a, Minister, f. 26, 27. — T. perparva, laevis, va- 

 lida, ventricosa, vix hians, subovata, postice rotundato-acuminata, 

 radii impressi expers, cute nitidissiina olivaceo-fiava vel olivaceo- 

 cinerea induta. Margo dorsalis posticus declivior, subrectus aut 

 retusus. Margo ventralis utrinque subsequaliter acclivis. Nates 

 eminentes. Arefe dorsales baud deunitse. Deutes magni, utrinque 

 circiter 12. — Very small, tumid or ventricose, scarcely, if at all, 

 gaping, variable as to shape, being ovate-oblong (rarely), subovate, 

 ovate, or ovate-trigonal, with the dorsal slopes (which seem to be 

 normally rather slight) ranging consequently from slight to de- 

 cided, and the veutral margin (which rises in a curve nearly 

 equally at both ends and is devoid of posterior refusion) from 

 slightly (in the elongated form) to greatly (in the trigonal variety) 

 arcuated ; devoid of indented ray, defined dorsal areas, or umbonal 

 ridge, with a highly polished olivaeeous-yellow or ashy-olive some- 



VOL. ni. k 



