558 dr. c. f. sonntag on the comparative anatomy 



The Pharynx. 



Phascolarctos cinereus. 



The distance from the fauces to the beginning of the cesophagus 

 is 4*5 cm., and the greatest width of the pharynx, which narrows 

 from before backwards, is 2'2 cm. The mucosa is smooth, and 

 two ridges run along the sides of the mid-dorsal line (text- 

 fig. 59, e). 



Text-fie'ure 59. 



The pharj'iix of Pliascolarctos cinereus. 

 Explanation of letters in text. 



The tonsils (text-fig. 59, c) are small oval bodies in the dorso- 

 lateral aspect of the pharynx, a little distance anterior to the 

 hyoid bone. They appear as pits on the interior of the pharynx, 

 and the right one is surrounded by a prominent ridge. 



The naao-pharynx. — The nasal fossse are prolonged backwards 

 by a conical tube, which opens on the mid-dorsal wall of the 

 pharynx by a small circular orifice guarded by two fleshy cushions 

 (text-fig. 59, A.d and 0). It has no mesial dorsal ridge as in 



