O CHITON. 



the shell, they are strongly striated longitudinally, and the 

 striae, when particularly examined, appear to be placed in 

 a quincunx order. The other six are formed in the inter- 

 vals of the marginal triangles, having their base on the 

 back of the shell, and are marked with curvilinear striae, 

 in a contrary direction. These, which may be called the 

 dorsal triangles, are perfectly smooth at the base The 

 margin resembles the skin of a snake, being covered with 

 minute black and white scales These scales are of the 

 same nature as the valves, and effervesce strongly in 

 mineral acids. The general colour of the shell is dark 

 brown, or olive : the interior always light green. 



Chemnitz, though he has quoted the synonyms of the 

 Chiton squamosus, has figured a distinct shell, and 

 Gmelin has unhappily jumbled together several species 

 under the same title. It seems that all those shells 

 with a scaly border, however they might differ in other 

 respects, were to be considered as varieties only of the 

 same species. This has produced much confusion in 

 thegenus, which it will be the object of the following spe- 

 cifications to rectify. The shell is an inhabitant of Ame- 

 rica. 



The scaly Chiton is well figured by Edwards, but 

 erroneously quoted by Linnaeus for Chiton aculeatus. 

 Born's figure is good, his description accurate. Speng- 

 ler's represention is most excellent, and the figures in 

 the French Encyclopedia are very good. Seba's figure, 

 quoted by Linnaeus, must be rejected, it is a bad repre- 

 sentation of the interior. Gmelin's variety £ is the 

 Chiton marginatus, Oscabrion gallicum of Argenville. 



