MOLLUSCS. 



349 



about, exposed to the full rays of the sun. They are littoral animals, occurring most 

 numerously near or just below low-water mark. The colors of the shells are bright, 

 or are laid on in pretty and striking patterns, while the animals are, if 

 possible, even more beautiful than the shells. Some of the species are 

 among the conchological rarities, and for them, in times 

 past, enormous prices have been paid. The rarest species 

 (or at least the highest priced ones) are C. guttata and C. 

 princeps. Certain species have always been highly prized 

 by savage races, and Cyprcea moneta, the money cowry, 

 passes, or used to pass, as the current medium of exchange 

 among some of the African tribes. It is a native of the 

 Pacific Ocean, and is brought in large numbers to Eng- 

 land and thence shipped to Africa to be used in barter. 



Among the sub-genera may be mentioned Trivia, Lu- 

 ponia, and Aricia, G. moneta being a representative of 

 the latter. Trivia strays into northern waters, one species being found 

 in European seas, while another is found in California. The sub-genus 

 Luponia is also represented by two species in the latter region. All 

 the species of Cyprcea are carnivorous, and they eat living or dead food. 



The species of Ovulum are to be recognized by their elongate shell, which, in some 

 forms, is greatly drawn out at the extremities, as in the weaver's-shuttle shell, 0. volva, 

 from the Philipy)ines. These shells are not so prettily marked as the cowries dre, but 



Fig. 453. —Trivia 

 californica. 



Fig. i5i.— Trivia 

 europtBa. 



Fig. 455. — Oimlum volva, weaver's shuttle shell. 



are usually more or less unicolored, and the color sometimes corresponds to that of 

 the surroundings, and the F'loridian species, Ovulum uniplicatum., is said to be yellow 

 or purple according to the color of the gorgonid corals on which it dwells, and on 

 which it is supposed to feed. 



The Strombid^ receive the common name, wing shells, on account of the broad 

 wing-like expansion of the outer lip in some of the species. Other 

 common names are applied to some of the members of the family. 

 The animals are among the most active of the molluscs. The long 

 and muscular foot is divided into two halves, adapting it for pro- 

 gression by a series of leaps instead of the ordinary creeping motion. 

 The operculum is also an aid in locomotion ; it is claw-shaped and 

 toothed on the outer edge, and these serrations are used to obtain 

 a foothold. Then the foot is straightened by a violent muscular 

 action, and the animal jumps forward. The other parts are 

 equally well developed, and seem to demand for these animals 

 a place near the top of the gasteropod series. The eyes are large 

 and placed at the extremities of the thick stalks, while the ten- 

 tacles are long and slender, the tentacles and eye-stalks being united for a portion of 

 their length. The muzzle is long and extensible. The strombs are carnivorous and 



Fig. 456. — Strombas 

 pugilis. 



