160 ON PERMIAN ENTOM08TnACA FROM 



bordered with a slight, narrow, raised rim, and somewhat 

 depressed ; tapering and more convex posteriorly ; ventral 

 border sinuous ; dorsal elliptical, shelving downwards pos- 

 teriorly to form a sub-acute angle with the ventral bor- 

 der ; dorsal aspect elongate ovate ; anterior broadly ovate. 



From Humbleton. Very rare. 



Dr. Reuss's 5'^{/rt?/a/rM??ig/iiw??i (" Jahresb. Wetter. 1848," p. 

 68, fig. 8), is not unlike G. Geinitziana in outline. 



5. C. BiPLicATA, Jones. PI. XI., figs, ha, 6h. 



Cytliere (^Cythereis ?) bijjUcata. Jones, in "King's 

 Monog. Perm. Foss.," p. 63, pi. 18, fig. 8. 

 Carapace sub-ovate, convex, bearing two short, longitudinal 

 rounded ridges, near the middle of the valve; dorsal and 

 ventral borders elliptical ; anterior extremity rounded; 

 posterior acute. 

 Fig. 5^ is a larger individual than the one figured in the 

 " Monog. Perm. Foss." (fig. 5a), and exhibits a modified form 

 of the plication or slight superficial ridge. 

 From Byers' Quarry. Rare. 



6. C. iNORNATA, M'Coy. PI. XI., fig. 6. M'Coy " Syn. Char. 



Carb. Foss.," p. 167, pi. 23, fig. 18. 

 Cythere {Cytlierella?) inornata. Jones, in "King's 



Monog. Perm. Foss.," p. 63, pi. 18, fig. 9. 

 Cytlierella inornata, Richter. " Zeitsch. Deut. Geol. 

 Ges.," vol. vii., p. 529, pi. 26, figs. 6, 7. 

 Carapace nearly oblong, sub-reniform, smooth, convex; dor- 

 sal border elliptical ; ventral almost straight ; anterior ex- 

 tremity obliquely rounded; j^osterior semicircular. 

 From Byers' Quarry. Rare. 



Dr. Richter has specimens of this species from the Zechstein 

 of the Saalfeld district. 



7. C. NUciFORMis, Jones. PI. XI., figs. 7a, 7h, 7c. 



Cythere {Cytherella ?) nuciformis. Jones, in " King's 

 Monog. Perm. Foss.," p. 64, pi. 18, figs. 11a, 

 Ub, lie. 



