1 



of the Galapagos Tortoise. 



449 



1 



the inner ridge is also serrated^ but very much less so. 



^ 



The lower surface of the upper jaw is marked by a 

 strong, prominent, serrated ridge with regularly inclined 

 sidesj and fitting exactly in the groove in the lower jaw; 

 on each side of it are deep grooves to receive the mar- 

 ginal ridges in the lower jaw ; these grooves again are 

 bounded by high, sharp ridges — the outer one is serrated 



and becomes more and more so as we proceed forwards, 

 till at last we come to three teeth, one on each side of 

 considerable size and one in the middle which is smaller; 

 directly behind these is a deep hollow to receive the large 



lower 



Mouth 



which is thin and quite firm, are seen the minute openings 

 of innumerable mucous follicles, but no trace of the spines 

 which are so conspicuous in the green turtle and some 

 others ; neither were they found m the oesophagus. The 

 follicles are much larger along the sides of the tongue 

 than elsewhere. Just inside the lower jaw and beneath 

 the tip of the tongue are two glands, of a flattened, ov^\ 

 form, one and a half inches long, one inch wide, and one 

 third of an inch thick ; on their surface are more than 

 thirty openings, some of them very large and all commu- 



■ . - 



nicating with cavities filled with a tenacious, transparent 

 mucus which collected repeatedly during the process of 

 maceration to which the parts were subjected. The 

 opening of the nostrils on the inside of the mouth is 



^ 



bounded on each si^e by a high ridge an inch long, and 

 probably intended to close the passage during the process 

 of the deglutition of air. 



The Tongue is a triangular, or, as it would commonly 

 be called, a heart-shaped organ. It is three Inches long 



VOL- I. PART IV. 



58 



