CHAPTER XII. 



Turban-Shells and Top Shells — Mother-of-Pearl— 

 The Little Shells— The Beautiful Caliostomas — 

 Brown, Black, Golden, and other Turbans — Pachy- 



POMA AND ITS NEIGHBORS — THE IyEPTONYX OF LlNN^EUS. 



WE have now reached the Trochidae, a great fam- 

 ily, which includes the Turban-shells and Top- 

 shells, and to which belong some of the most beauti- 

 ful and interesting of all our mollusks. 



We shall find little ones and big ones; shells black 

 as night, and shells red as bricks; some shells with 

 little beauty, and others composed of brilliant pearl, 

 and marked with richly colored stripes; some thick 

 and heavy, made for the sport of the waves, and oth- 

 ers so thin and delicate that you can crush them with 

 your fingers. The inner layer of these shells is 

 nacreous, that is, composed of that rainbow tinted 

 substance called mother-pf-pearl. All the mollusks 

 of this great family may be classed with the vegeta- 

 ble-eaters. 



The first species that I shall mention is named 



Margarita piipilla, Gld., Mar-gar-i'-ta pu-pilMa, and 



its shell is represented in Fig. 63. This pretty 



little Turban is a northener, living in and 



about Puget Sound, but sometimes coming 



Fig. 63. f ur ther south. Its whorls are four, marked 



with spiral ridges ; its umbilicus distinct, and its 



