59 
B. bistriatum, and B. decussatum, of Lamarck, are, I suspect, both 
found in the Essex cliff. 
XXII. Eburna. An oval or elongated univalve, the right edge very 
entire ; the opening oblong, and notched at the bottom ; the columella 
umbilicated, and slightly grooved at its base. 
Buccinum glabratum, Linn. Lister, Tab. 974, Fig. 9, is given as 
the type of this genus by Lamarck, who mentions this genus only in 
his Systeme des Animaux sans vertebres, not noticing it at all among 
the fossils of the environs of Paris. A shell, however, exists among 
the Essex fossils, which, except in having the columella hardly um- 
bilicated, seems very nearly to approximate to this genus, and to the 
particular shell B. glabratum, which is given as its type. 
This shell, which I will venture to call E. glabrata, is figured 
Plate V. Fig. 25. 
XXIII. Terebra. A turreted and subulated univalve : the opening 
short, and notched in the lower part. The basis of the columella 
twisted. 
Two species of this genus are found in the environs of Paris : T. pli- 
catula and T. scalarina. T. plicatula is represented Plate V. Fig. 7- 
XXIY. j Dolium. A subglobular ventrose univalve, ribbed circu- 
larly across ; the right lip dentated or crenulated through its whole 
length. The opening oblong, ample, and notched at the bottom. 
No shell of this genus appears to have been found fossil. 
XXV. Harpa. An ovate, ventricose univalve, with longitudinal 
compressed ribs, terminating superiorly in an angle or a point ; the 
opening notched in the lower point, and with no canal : the colu- 
mella smooth, with an acute base. 
This genus comprises those shells which had been referred by Lin- 
naeus to the genus Buccinum, and entirely to the species Buccinum 
harpa. These shells, like most of those which have been already 
mentioned, are sea shells, and are inhabitants of the warmer climates. 
The only shell which I have of this genus, is one which, although it 
