620 MR. E. B. POULTON ON THE [DcC. 18, 



into these by a lessening of the posterior cornified part until it 

 ceases to differ from the rest of the ring. 



B. The Filiform Papilla are probably normal in structure, as they 

 are in shape and position. 



Thus this tongue comes nearest to Perameles in the circumvallate 

 papillae, but is very peculiar in the coronate papillae, and primitive 

 in the possession of isolated hair-like papillae. 



General Conclusions. 



The above observations may be shortly recapitulated, and the 

 tongues of all the Marsupials yet examined may be classified as 

 follows (the types are printed in italics): — 



I. A. Circumvallate papilla approximately identical, bilaterally 



symmetrical ; much protected (the mouth of the involution 

 probably capable of closure), and the pointed apex directed 

 forward (exc). The taste-bulbs ascend high up the papillary 

 sides in the most typical instances. Posterior angle very 

 obtuse (exc). 



B. Lateral organ very primitive, and showing its origin as a row 



of gland-ducts. 



C. Coronate papilla with irregular circles of secondary papillae 



(in some places). Intercalated single hair-like papillae 

 present. 



Halmaturus ; Macropus ; Petrogale ; Dasyurus (?). 



II. A. Circumvallate papilla. — The two anterior are smaller and 



of the type desci'ibed above, altliough sometimes present- 

 ing the characters to a less degree ; the posterior larger, 

 and radially symmetrical ; the summit is a circular disk 

 which can be seen from the surface ; the whole papilla 

 resembles that of the higher mammals (except for the con- 

 stricted base). Posterior angle acute. 



B. Lateral organ. — Less primitive ; an irregular row of slit-like 



furrows ; gland-ducts distinctly open at the bottom of the 

 furrows. 



C. Coronate papillce less irregular ; no intercalated hair-like 



papillae. 



Phalangista ; Belideus ; Acrobates. 



III. A. Circumvallate papilla approximately identical and of the 



same type as the posterior papillae of Division II. Posterior 

 angle varies. 



B. Lateral organ absent. 



C. Coronate papillce very regular ; no intercalated hair-like 



papillae. 



Perameles; Didelphys ? (does not follow C). 



It is very interesting (and I venture to think significant) that the 

 structural features which combine together to make one of the 

 abuve divisions show considerable correlation with one another. 



