PIERCED SHELLS AND CHITONS 



261 



Fig. 259 



Katherina tunic at a^ Sby., the Black 

 Chiton, Figure 259, was named in honor 

 of Lady Katherine Douglass, who hrst 

 sent a specimen to the British Museum. 

 The shell is oblong and elevated, the 

 valves being mainly covered by the black, 

 leathery girdle. This singular arrange- 

 ment of the parts is so striking that a 

 specimen cannot be mistaken for any 

 other species. Think of a smooth, black skin, rounded 

 like a whale's back, and set along the center with 

 eight little shelly plates, and you will get the idea. 

 The plates, where they are not exposed, are white; 

 elsewhere they are dark brown or discolored. 



The hgure shows the appearance of a small speci- 

 men, for they sometimes grow to a length of three 

 inches. This species thrives especially in the far 

 north, but it ranges southward as far as Catalina 

 Island. The soft parts are salmon colored, at least 

 in the northern specimens. It is eaten raw by the 

 natives oi the northwest coast. 



Amicula pallasii^ Midd., the Concealed Chiton, 

 has a shell nearly concealed by the hairy mantle, 

 which is almost circular, and which covers the back 

 of the animal except for eight small holes. This 

 mantle, or girdle, bears unequal bunches o\ reddish 

 hairs. Its length is 67 mm., and it lives in far 

 northern waters. 



We close our description of these creatures with a 

 few words concerning the largest one of all, named 

 Cryptochiton stelleri^ Midd., the Giant Chiton, 

 which has already been referred to on a previous 



