154 CYFRJEWJE. 



polish and brilliant coloring; spire nearly, if not entirely, 

 covered by the body-whorl which envelops it ; aperture nearly 

 central, narrow and longitudinal ; lip and columella more or 

 less toothed the entire length ; occasionally, but rarely, without 

 teeth. 



The young shell differs in being Bulla-shaped ; the columella 

 is smooth, the outer lip thin, and the color diffused in bands or 

 waved lines. As the animal grows, the lip and columella 

 thicken, teeth begin to develop and the shell becomes more 

 solid. The two unequal lobes of the mantle extend one from 

 either side of the aperture, and meet upon the dorsal surface of 

 the shell, producing at the point of contact what is known as 

 the " dorsal line " or " sulcus." The function of the mantle is 

 to deposit the calcareous substance which forms the richly 

 colored enamel of the shell. 



The cowries are shy and move slowly ; they inhabit the warm 

 seas of the tropics, though a few species occur farther north, 

 notably Trivia Europsea, which has been found on the coast of 

 Norway, and is abundant on the shores of Great Britain, 

 ranging from the verge of low-water to as deep as fifty fathoms. 

 The highest northern station on the west coast of America^ at 

 which any representation of the Cypraeidae has been detected, is 

 Bodega Head, Cal., in lat. about 38 north (Stearns). 



They feed largely upon coral animals. Those found on some 

 of the islands near New South Wales are usually seen lying 

 upon deep beds of dead shells of the genus Pectunculus. 

 Fossil, the Gyprseidse commenced in the Cretaceous, and have 

 augmented in the number of species to the present time. One 

 species is reported from the Upper Jurassic of Sicily. From 

 the fact that in many species of Cyprsea small shells are found 

 fully adult, while larger examples appear less matured, theories 

 about casting or dissolving and renewing the shell at different 

 periods of the animal's existence have" been advanced by several 

 eminent authorities. Bruguiere first expressed this opinion. 

 His belief was that the animal left its shell to form a new one, 

 after the manner of crabs. Lamarck coincided with this view, 

 but Deshayes doubted the ability of the animal to secrete a new 

 shell complete in all parts, after it had reached an advanced 

 condition of existence, and considered the difference in size was 



