136 EOCENE MOLLUSCA. 
No. 79. Ovutar antiqua. fF. &. Edwards. Tab. XVII, fig. 3a—d. 
O. testa elongato-ovali, sub-ventricosd, postice sub-acuminatd, levi : apertura angustd, 
postice elongata, in canali brevi, mediocriter lato, exeunti, anticé effusd. 
Shell of a lengthened oval form, somewhat ventricose in the middle, slightly 
acuminated at the posterior extremity, smooth: aperture elongated, narrow behind ; 
posterior canal short, moderately wide. The anterior extremity is broken; it 
appears to have been rather more obtuse than the posterior one. The last volution is 
smooth, but the surface of the preceding volution presents numerous transverse striz, 
perspicuous towards the posterior extremity, and becoming obsolete as they approach 
the middle of the whorl; these strize are very fine, so much so as to be barely per- 
ceptible by the naked eye. 
The only specimen I have seen forms part of Mr. Wetherell’s collection ; it is too 
imperfect for a detailed description, or even for ascertaining satisfactorily the genus to 
which it belongs. It is apparently an immature shell just emerging from the first stage 
of growth before the outer lip has become thickened or involute, and when the absence of 
teeth on the columella is not conclusive of the genus. It may be the young shell of a 
Cypreea, resembling the C. acuminata of Melleville, and, therefore, I have referred it to 
the present genus with doubt, and have named it provisionally only. 
Stze-—Axis, } an inch; diameter, 2-10ths of an inch. 
Locality—Primrose Hill. 
Genus 22d. MARGINELLA.* Lamarck. 
PoRCELLANA, PERIBOLUS, Adanson, 1757. 
Dactrytus, Humphrey, 1797. 
MAarGINELLA, Lamarck, 1801. 
Marcinetius, Montfort, 1810. 
PersicuLa, Schum., 1817. 
Votvarta, (sp.,) Lamarck, 1822. 
MARGINELLA, GLABELLA, ; 
VoLuTeLLA, GIBBERULA, § Swainson, 1840. 
Pux®Nosprra, Cryprosprra, Hinds, 1844. 
Gen. Char.—Shell oval, oblong, smooth, enamelled; spire short, sometimes almost 
concealed: aperture elongate, narrow, truncate, sometimes broadly but not deeply 
notched in front; outer lip thickened externally, inner margin sometimes smooth, 
generally crenated ; columella with distinct plaits, more or less numerous. 
* Etym., Diminutive of JZargo, a rim or margin. 
