"In the second section are-- _Tellina_ _Tellina_. _Tellinides_ _Tellina_. _Corbis_ _Venus_. _Lucina_ _Venus_ and _Tellina_. _Donax_ _Donax_. _Capsa_ _Donax_. _Crassina_ _Venus_. [Sidenote: CORBIS. LUCINA. CAPSA. CYCLAS.] "There is but one species of _Tellinides_ from the island of Timor. The genus _Corbis_ is fossil, with one exception, _Corbis fimbriata_, from the Indian Ocean. _Lucina_ is a pretty genus of shells. _L. carnaria_ is frequently found in collections. The interior of the valves is of a deep red colour: the muscular impressions are very distant from each other; one is greatly lengthened out; the valves delicately striated. _Capsa_ is taken, you perceive, from _Donax_. "_Tellina_ is found fossil on the borders of the Red Sea, also in the county of York. Of _Donax_ and _Mactra_ the fossil species are few. "In the third section of this order we find six families. 1st. _Conchæ_, which are of two kinds, fluviatic, living in fresh-waters; and marine, or living in the sea. Of the first are, _Cyclas_, taken from _Tellina_. _Cyrene_, partly from _Tellina_ and _Venus_. _Galathea_, _Venus paradoxa_, (one species.) "_Cyclas rivicola_ (Plate 9.) will give you an idea of this genus: it is _Tellina cornea_ of Linnæus. The species are very common in lakes, rivers, and ponds: it abounds in river-sand, from which you may often procure perfect specimens. Lamarck observes that it is rare in France; but appears common in the Thames. [Illustration: Plate 9.] [Sidenote: POTAMOPHILA. ASTARTE. PULLASTRA.] "_Cyrene_ is a foreign genus. "In the _Conchæ marìnæ_ the genera are very numerous. They are all assembled under the _Venus_ of Linnæus. Lamarck reduced the genus; but it has been yet further divided by later writers. _Cyprina_, } _Cytherea_, } From _Venus_, Lamarck's genera. _Venus_, } But _Pullastra_, _Astarte_, _Venerupes_, and _Potamophila_ have been since withdrawn from the original genus. * * * * * "_Pullastra_ was the name of a species, and includes _V. pullastra_, _V. papilionacea_, _V. decussata_, _V. litterata_, _V. virginea_. "_Astarte_ includes some British species, _V. Scotica_, &c. [Sidenote: VENUS. CYTHEREA. ISOCARDIA.]