A1 Saturday and Sunday, or Friday evening until Sunday night; the part of the week in which many people living in the West do not go to work: This/Next weekend we're going to see some friends. I have a lot of homework to do over the weekend. He spent the weekend fishing with his brother.
List of mollusks. 1  class Aplacophora. 2  clams, mussels, oysters, and scallops (class Bivalvia) 3  octopi, squid, cuttlefish, and nautili (class Cephalopoda) 4  snails and slugs (class Gastropoda) 5  class Monoplacophora. 6  class Polyplacophora. 7  class Scaphopoda. 8  extinct mollusks.
There are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpets, land snails and land slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number.The fossil history of this class goes back to the Late Cambrian.There are 611 families of gastropods known, of which 202 are extinct and appear only in the fossil record.ome of the more familiar and better-known gastropods are terrestrial gastropods (the land snails and slugs) and some live in freshwater, but more than two thirds of all named species live in a marine environment.