PLATE XXI. 
Eurydesma cordatum, Morris. 
Partly testiferous left valve with a produced umbonal region. 
Eurydesma hobartense, Johnston. 
Interior of rather more than half a testiferous left valve with a nearly complete resilifer, 
small cardinal fold, and large inflection for tlie reception of the fold of the right 
valve; the interior is filled with limestone. 
Umbonal i-egion and articulus in part of a testiferous left valve (see PI. XXII, fig. 1 ; 
PI. XXIII, fig. 5), displaying a highly produced anterior end, a flattened lunular 
depression, and portion of the resilifer. 
Eurydesma cordatum, var. ovale, E. & D. 
Internal cast of a right valve, exhibiting the casts of the resilifer, cardinal inflection, 
visceral retractor scars, radii, and undefined pallial impression. 
A smaller internal cast of a right valve (see PI. XXV, fig. 2) displaying the sharp, 
cardinal margin, and line of visceral retractor scars. 
Localities. 
Fig. 
1. 
Mount View, near Cessnock. 
Figs. 2, 
3. 
Maria Island, Tasmania. 
Figs. 4, 
5. 
Ravensworth Quarry, near West Maitland. 
