352 The Commercial Products of the Sea. 



so fine and of such beautiful colours as to be employed for 

 various purposes of art. It is only those, however, of the 

 hawksbill and caret species that possess any great trade 

 value ; the plates being stronger, thicker, and clearer than 

 in other varieties. There are usually 13 plates on the 

 carapace, called collectively in trade " the head," — four on 

 each side, and five on the back; the last bent in the centre. 

 Of the side plates, the two middle are the most valuable, 

 being the largest and thickest ; those on the back and 

 margin, known as " hoofs " or " claws," are comparatively of 



Fig, 26. 



Hawksbill turtle. 



less value. There are 24 marginal pieces round the edges, 

 which are termed the " feet " or noses." The lamellce or 

 plates vary in thickness from one-eighth to one-quarter of 

 an inch, according to the age and size of the animal, and 

 weigh collectively from four to six pounds or upwards. In 

 an animal of ordinary size, about three feet long and two 

 and a half feet wide, the largest plates weigh about nine 

 ounces, and measure about thirteen by eight inches, and 

 are a quarter of an inch thick in the middle. 



