and its Fossil EsthericB. 



353 



On specimen 302 a there is one individual (Fig. 1) wliicli has 

 retained in great part the shape of the bivalved carapace, but is 

 rather narrowed vertically. The left valve remains exposed, and 

 a portion of the dorsal region of the other valve protrudes beyond it. 



This left valve has the oblong-ovate shape common in the genus, 

 and bears indications of numerous concentric close-set lines or 

 ridges. It measures 5 mm. in length and 3 mm. in height. 



X. 6 



Fig. 1. — Estheria anomala, sp. nov. Carapace shomng the left valve, somewhat 



narrowed by crush. Magnified 8 diam. 

 Fig. 2. — A right valve", crushed quite flat. Magnified 8 diam. 



A modified right valve (Fig. 2), on the same specimen, quite 

 smooth, and widened out by pressure until it is almost suborbicular, 

 measures 5-75 mm. in length and 4-5 mm. in height, and yet may be 

 of the same species as the foregoing, there being many intermediate 

 shapes on the bed-planes of this rock. 



On specimen 300 a are other flattened valves, often nearly sub- 

 orbicular. Fig. 3, which has a short and broad ovate form, with an 

 apparently short but distinct dorsal border or hinge-line, measures 

 6-25 by 4-25 mm., and may be taken as belonging to the specific 

 type. The spaces between the concentric ridges (Fig. 4) exhibit no 

 ornament. 



;;|| i »]i i u.i. ii L i m 



« WMjM-U;«/'.'ft ' 



Fig. 2,.— Estheria. anomala, sp. nov. A right valve, somewhat misshapen by pressure. 



Magnified 8 diam. 

 Fig. 4.— Part of the surface of Fig. 3. Magnified 75 diam. 



None of the Estherice above mentioned from the Enon Con- 

 glomerate of Heidelberg correspond with the three known South 

 African species : — 



Estheria Greyii, Jones : Geol. Mag., 1878, p. 100, PI. Ill, Fig. 1. 

 This difi'ers altogether in the general shape. It was from the 

 Lower Karoo beds, near Cradock, Cape Colony. 



DECADE IV. VOT,. VIII. — NO. VIII. 



23 



