14 MOLLUSCA FROM THE CRAG. 



1. Ovula Leathesii. /. Sow. Tab. II, fig. 1, a — b. 

 Ovula Leathesii. J. Sow. Min. Con. t. 478, 1824. 



— Nyst. Coq. foss. de Belg. p. 605, pi. 43, fig. 19, 1844. 



Calpurna Leathesii. Flem. Brit. An. p. 331, 1828. 

 Ovula Leathesii. S. Wood. Catalogue 1842. 

 Ovulum Leathesii. Morris. Catalogue, p. 155, 1843. 

 Bulla spelta. Linn. 

 0. Tcstd elongato-ovatd,fusiformi, medio ventricosd, utrinque subacuminatd ; aperturd 

 snperne lineari, inferne sub-effusd ; labro intus incrassato, subtus rotundato-angulato ; 

 columella superne uniplicatd. 



Shell elongato-ovate, fusiform, smooth, rather ventricose in the middle, slightly 

 acuminated at each extremity ; aperture contracted above, and a little expanded at 

 the lower part, with a very short canal ; outer lip thickened within, reflected on the 

 exterior ; inner lip thin, expanded, with an obtuse fold upon the upper part, above 

 the spire. 



Axis, yf of an inch. 

 Locality. Cor. Crag, Sutton. 



Red Crag, Walton Naze. Recent, Mediterranean. 



This is at present rare in the Red Crag, and I have only a fragment from the 

 Coralline Formation. It is in an altered condition, some of the outer coating has 

 gone, leaving the reflected outer lip separated from the shell. There are some 

 faint traces of denticulations upon the inside of the outer lip, as well as a few strias 

 upon the lower part of the shell ; the inner lip is depressed, slightly concave, with 

 a projecting callosity inward. So far as the altered state of this shell will allow of 

 a fair comparison, I do not see any good specific character by which it can be 

 separated from Bulla spelta of Linnasus, which is given as a Touraine fossil by 

 Dujardin (Mem. de la Soc. Geol. de France, 1837, p. 302.) 



Gen. Cype^a,* Linn. 1740. 



Pekibolus (spec.) Adanson. 1/57. 

 Coccinella, Leach. 1820. 

 Trivia, Gray. 1830. 



Gen. Char. Shell oviform, oblong, or subglobular, with a short depressed spire, 

 visible only in the young state ; covered with a coating of enamel in the adult. 

 Aperture linear, as long as the shell, crenulated or denticulated on both sides, 

 terminating at both extremities in a short canal, with an inflected and inflated 

 outer lip, generally smooth, sometimes pustulous, or transversely ribbed. 



In my Catalogue the species belonging to this genus were enumerated under 

 the name of Trivia, proposed by Mr. J. B. Gray, for the reception of those species 

 which are transversely ridged or sulcated upon the exterior ; as the animals, how- 

 ever, are known not to differ in any essential character from true Cypraaa, I have 



* Etym. Cypris, one of the names of Venus. 



