76 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 
Astarte Batuonica, Lye. ‘Tab. XL, figs. 238, 23 a. 
Testa ovato-trigona, crassa gibbosa ; umbonibus sub-anticis antrosum curvatis ; lunula 
cordata, excavata, marginibus rotundatis, latere postico obtusangulo formante, superficie costis 
regularibus, rotundis, crebris, concentricis, marginibus interne denticulatis. 
Shell ovately trigonal, thick, gibbose ; umbones anterior and curved forwards; lunule 
excavated, cordate, its margins rounded ; the posterior side has an obtuse, oblique angle ; the 
surface has closely arranged, rounded, regular, concentric coste ; the margins of the valves 
are denticulated internally. 
Height, 6 lines; opposite diameter, 5 lines; diameter through the valves, 43 lines. 
A short and very convex, thick, shell, with elevated umbones and slightly truncated 
posterior border, which is pointed at its inferior extremity, near to which is a large fold of 
growth. 
Geological Position and Locality. Wampton, Cliffs near Bath ; collected by W. 
Walton, Esq., who states that, having found it at the base of the cliffs, some doubt may 
exist as to its real geological position. ‘The mineral character of the specimen is ferru- 
ginous and identical with that of the bed of Great Oolite Corals and of other shells which 
unquestionably belong to the Great Oolite. 
Astarte rustica, Walton, MSS. Tab. XXXV, fig. 5; Tab. XL, f. figs. 8, 8 a. 
Testa parva, crassa, ovato-oblonga, plano-convexa, umbonibus parvis, antemedianis, 
acutis, margine, cardinali brevi, subhovizontali, antice rotundato, basi subarcuato, marginibus 
internis dentatis ; lateribus costis angustis imprimis regularibus, deinde inequalibus. 
Shell small, ovately oblong, moderately convex, with thickened margins, internaly den- 
ticulated ; umbones anterior to the middle of the valves, curved forwards, and acute ; hinge- 
border short and horizontal, terminating in an obtuse angle. The anterior border is 
rounded; the lunule is only slightly excavated ; the base line is nearly straight; the sur- 
face of the valves has an obscure, posterior, oblique angle ; the coste are narrow, at first 
regular, afterwards they become irregular and crowded. 
Length, 5 lines ; height, 4 lines; diameter through the valves, 3 lines. 
Much variability exists in the promimence and arrangement of the costa, which are 
sometimes very numerous and nearly obsolete, or they are distant and elevated. A little 
species, allied to 4. Voltzii, Roem., A. recondita, Phil., and the young of 4. rhomboidalis, 
Phil. ; neither of these species, however, has the test so thickened towards the margins. 
Geological Position and Locality. The Forest Marble of Laycock, Somerset ; in the 
cabinet of W. Walton, Esq. 
