42 CALIFORNIA SEA-SHELLS. 



farther northward, on the Oregon coast, and 

 even about Sitka. And here we may say that 

 a large number of the descriptions contained in 

 this little book apply as well to the shells of Or- 

 egon and Washington Ty., as to California. Some 

 of the species are much finer on the northern 

 coasts, than on our own. Tonicia lineata, Wood, 

 Painted Chiton, (not figured), is a small species, 

 about an inch in length, with smooth and naked 

 mantle, and eight polished valves, beautifully 

 striped and painted. The chief color is orange, 

 and the markings are white and dark reddish 

 brown. Within, the valves are white, shaded 

 with orange. Living specirners are found at 

 very low water, but single red valves are often 

 washed ashore. 



White, butterfly - shaped shelly plates may 

 often be picked up among the rocks, from one to 

 two inches in length ; and from their singular 

 appearance they have been called " Butterfly 

 Shells." They are, really, single valves washed 

 from the dead body of the Giant Chiton, Cryp- 

 lochiton Stelleri, Midd., a huge mollusk some- 

 times found entire. It is six inches in length, 

 and three in breadth ; the white valves are 

 wholly concealed beneath the reddish brown, 

 hard, gritty mantle, which covers the whole 

 back of the animal. Thus the mystery of the 

 " Butterfly Shells " is explained, and they be- 

 come of more interest, since we know their true 

 origin. 



The little shell shown in Fig. 2, PI. XI, be- 

 longs to the sub-class which also includes the 

 Bubble-shells, and the Sea-slugs, or naked mol- 



