76 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 



ASTARTE BATHONICA, Lye. Tab. XL, figs. 23, 23 a. 



Testa ovato-trigona, crassa gibbosa ; umbonibus sub-anticis antrosum curvatis ; lunula 

 cor data, excavata, marffinibus rotundatis, latere postico obtusangulo formante, superficic costis 

 regularibus, rotundis, crebris, concentricis, marginibus interne denticulatis. 



Shell ovately trigonal, thick, gibbose ; utnbones 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 costas ; the margins of the valves 

 are denticulated internally. 



Height, fi lines ; opposite diameter, 5 lines ; diameter through the valves, 4| 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. Hampton, 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-convcxa, umbonibus parvis, antemedianis, 

 acutis, margine, cardinali brevi, subhorizontali, antice rotundato, basi subarcuafo, marginibus 

 internis dentatis ; lateribus costis angustis imprimis regularibus, deinde in&qualibus. 



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 costse 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 prominence and arrangement of the costse, which are 

 sometimes very numerous and nearly obsolete, or they are distant and elevated. A little 

 species, allied to A. Voltzii, Roem., A. recondita,Phi]., and the young of A. rhomboidulis, 

 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. 



