18 MULTIVALVES. CHITON. 



cartilaginous substance, capable of sufficient distention 

 and contraction, to admit of considerable action or play 

 on the part of the valves ; so much so, that the animal 

 can at pleasure convert its shell into the form of a ball, 

 and thereby assume the appearance of a little insect, well 

 known as an inhabitant of old and decayed wood. 



The covering and coloring- of the valves serve to create 

 distinction; some being perfectly smooth, others nodul- 

 ous, or knobbed; some beset with spines, prickles, or 

 hairs; and others, again, are striated, dotted, and rayed, 

 as the C. hispidus, C. squamosus, and C. marmoratus. 



The color of the exterior is frequently a dusky brown, 

 often passing into ditferent shades of olive-green : others 

 partake of a reddish or pinkish tint; whereas some spe- 

 cimens are of an ochreous or yellowish-white complexion ; 

 and many have their valves adorned with elegant designs 

 and.marblings (not unlike tattooing) in the liveliest co- 

 lors imaginable. 



The interior also admits of much variation with regard 

 to color; however, the most prevalent is that of a blueish- 

 white, often beautifully diversified with cloudings of yel- 

 low, brown, light green, and pink. 



The margin, which confines the valves in their proper 

 situations, differs materially in the various species: in 

 some instances, it is smooth and of a yellowish-brown co- 

 lor; generally, however, it is beset with fine scales, of a 

 green or olive color; frequently it is of a reddish tint, 

 and in some species it is dusky-brown, or even black. 



The situation and formation of the valves throughout 

 the genus resemble the plates which constitute a suit of 

 armour or coat of mail ; and it is from this marked simi- 

 larity that the Chiton has derived its name. 



