[56a]

Below Buenos Ayres & not far from the Ensinade de Barre, from 1 to 6 leagues inland from the present shores of the River are found vast bank of marine shells which are quarried for lime; - in some places they are so compact as to form a recent lime stone sufficiently hard for building, the church of Maydalena on the Coast for example is built of it – on being first dry it is soft & easily worked bit ut become extremely hard after long exposure to the air. The following are some of the Shells on these Beds of which

[57av]

I have specimens - - Mr Sowerby was good enough to name them for me.

Voluta Colocynthis of Tillwyn

Voluta Angulata - Swainson

?? Buccinum – Chemnitz

[Annotation by Darwin:] Globulosum Kierner cochlidium–

[Annotation by Darwin:] like or from Bahia

Buccinum Nov. Spec.

Ditto --- Ditto

Oliva patula --- Solander

[Annotation by Darwin:] very like my Buenos Ayres specimen

Mactra? or type novi genesis

Cytheræa novi spec: -

[Annotation by Darwin:] purpurascens (perhaps) } same as Bahia Blanca

Venus Flexuosa

Ostrea

[Annotation by Darwin:] Buccinum Globulosum of Kierner