14 MOLLUSCA FROM THE CRAG. 



I. Oa^ula Leathesii. /. So7c. Tab. II, fig. 1, a—/j. 



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



_ Ni/st. Coq. foss. de Belg. p. G05, pi. 43, fig. 19, 1844. 



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

 OvuLA Leathesii. -S. Wood. Catalogue 1842. 

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

 Bulla spelta. Linn. 

 0. Testa elongato-ovatd, fasiformi, medio ventricosd, utrinque subacuminatd ; aperturd 

 siiperne lineari, in/erne sub-effiisd ; lahro intus incrassato, subtiis rotundato-angulato ; 

 cohimeUa siiperne uniplicafd. 



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, II 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 Up, as well as a few striae upon the lower 

 part of the shell ; the inner lip is depressed, shghtly concave, with a projecting 

 callosity inward. So far as the altered state of this shell will allow of a fair com- 

 parison, I do not see any good specific character by which it can be separated from 

 Bulla spelta of Linnaeus, which is given as a Touraine fossil by Dujardin (Mem. de la 

 Soc. Geol. de France, 1837, p. 302.) 



Gen. CypRjEA,* Linn. 1740. 



Pekibolus (spec.) Adanson. 1/57. 

 CocciNtLLA, Leach. 1820. 

 Tkivia. 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 adidt. Aper- 

 ture 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 Tri\aa, proposed by Mr. J. E. Gray, for the reception of those species which 

 are transversely ridged or sulcated upon the exterior ; as the animals, however, are knowii 

 not to differ in any essential character from true Cypraea, I have accordingly restored 



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



