Xenophora
Xenophora, commonly called carrier shells, is a genus of medium-sized to large sea snails, marine gastropod mollusks in the family Xenophoridae, the carrier snails or carrier shells. The genus "Xenophora" is the type genus of the family Xenophoridae. Etymology. The name "Xenophora" comes from two ancient Greek words, and means "bearing foreigners", so-called because in most species the snail cements pieces of rock or shells to its own shell at regular intervals as the shell grows. Description. The shells of species within this genus vary from small to large (diameter of base without attachments 19-90 mm ; height of shell 21-60 mm), depressed-conical, with narrow to very narrow, simple peripheral edge, non-porcellanous ventrally. Foreign objects are attached to all whorls, with generally more than 30% of dorsal surface obscured by these objects. The foreign objects are usually medium-sized to large. Although the foreign objects are usually mollusk shells, pebbles, or small pieces of coral rock, in some instances a bottle cap has been attached by the snail to its shell. Species. The genus "Xenophora" includes the following species and subspecies: Extinct species. Extinct species within this genus include: Fossil record. Fossils of "Xenophora  are found in marine strata from the Cretaceous to Quaternary (age range: from 89.3 to 0.012 million years ago.). Fossils are known all over the world.