158 EOCENE MOLLUSCA. 
would rather imply that it is a tender shell; but this does not appear to be so with 
Mr. Edwards’s specimens. 
It is well known that beds of fowr different ages occur in the Cliff near Herne Bay ; 
but all the specimens of this species that I have seen appear to have come from the 
Thanet Sands. 
Fig. 8, Tab. XXTV, represents a specimen from a well at Hampstead, which probably 
belongs to this species. It is rather more ridged than the Herne Bay specimens, and it 
has a more elevated umbo. I have given to it the provisional name of J. ¢enera var. 
Hampsteadiensis. 
5. Astartr? mopicetua, S. Wood. Tab. XXI, fig. 2 a, 6d. 
Spec. Char. A. Testd minimd, ovato-subtrigond, compressiusculd, levigatd, valde ine- 
quilaterali ; latere postico brevissimo, obtuso, subtruncato, antico producto, obtuso ; umbo- 
nibus minimis ; cardine brevi, unidentato, dentibus lateralibus nullis ; margine integro. 
Shell small, ovately triangular, somewhat depressed, smooth externally, very inequi- 
lateral ; pedal side large and obtuse ; umbo small; hinge of right valve with one denticle ; 
margins smooth. 
Diameter, =;th of an inch. 
Locality. Stubbington (Hdwards). 
A single valve, as represented, is in Mr. Edwards’s cabinet. It is a right valve, with 
its dentition somewhat like that of Asfarfe in having only one triangular and _ slightly 
diverging cardinal tooth; but it has no lateral denticle on the pedal side. In my 
Monograph of the Crag Mollusca are introduced several species of small bivalves, which 
accord with the diagnosis of Asfarte, one of which (¢riangularis) was made the type of 
a new genus (as is well known) under the name Goodallia by Turton, who erroneously 

considered it as having an internal connector; and it was called AZactra by his predecessor 
Montagu ; but it possesses all the characters of Astarte. 
There are some bivalves belonging to the Hocene Period which have been figured and 
described by M. Deshayes under the generic name of Goodallia (‘Dese. des An. sans 
vert. du Bas. de Par.,’ t. i, pp. 783—786, pl. 63). These resemble in outward form and 
magnitude the small species of Crag bivalves to which I have referred ; but they appear 
to exhibit a difference in the dental furniture, reversing as it were the formula of the 
genus Asfarte ; the right valve having two diverging teeth or denticles with a triangular 
cavity between them, into which a large triangular tooth is inserted from the left valve 
(that is, according to the representations), contrary to what it is in Asfarte, where the large 
triangular tooth is in the right valve, and the two diverging teeth in the left. It is 
expressly stated in the diagnosis of Goodallia by Deshayes, that the margins are in- 
variably smooth. “Les bords sont simple sans aucune trace de dentalures ;” p. 782. 
