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.
clams, mussels, oysters, and scallops (class Bivalvia) 1  ark shell (family Arcidae) 2  cockles (family Cardiidae) 3  coquina clam (genus Donax) 4  gaper clams (Tresus nuttallii and Tresus capax) 5  geoduck (Panopea generosa) 6  jingle shells (family Anomiidae) 7  mussels (families Mytilidae and Unionidae) zebra mussel (genus Dreissena) 8  genus Nuculana.
Â© Jonathan Bird/ORG. For educational use only. There are over 50,000 known species of Mollusks, which makes them second only to the Arthropods in invertebrate phylum size. Among the Mollusks are some of the most well known of invertebrate sea creatures, like snails, clams, mussels, squid, and octopods.Although one might not see an obvious physical relationship between a snail and a squid, they are remarkably similar in construction.n general, mollusks have 3 body regions: a head, a visceral mass, and a foot.. The head contains the sense organs and brain, while the visceral mass contains the internal organs. The foot is the muscular lower part of the body which is in contact with the substrate.