4 MAMMALIA. 



4. LUTRA. Grinders five above and five or six 

 below : body long : feet short, with five palmated toes : 

 head depressed : ears very short : tongue slightly rough : 

 tail flattened horizontally. 



5. CANIS Grinders six above and seven below on 



each side ; the two last in each jaw tubercular : ears 

 moderately large : tongue smooth : claws not retractile. 



(1. CANIS.) Pupil circular. 



(2. VULPES.) Pupil linear: tail bushy. 



6. FELIS Grinders four above and three below on 



each side ; no tubercular grinder in the lower jaw : tongue 

 armed with prickly papillae pointing backwards : claws 

 retractile. 



** Teeth various : feet short and fin-shaped, adapted 

 to swimming ; those behind horizontal. 



7. PHOCA Incisors and tusks in both jaws : grinders 



uniform ; each of three lobes ; the central lobe triangular, 

 large and cutting, the anterior and posterior lobes small. 



8. TRICHECHUS No incisors or tusks in the lower 

 jaw: tusks in the upper jaw greatly produced, directed 

 downwards : grinders cylindrical, short, and obliquely 

 truncated. 



*** Incisors varying in number : summits of the 

 grinders with conical points : soles of the hinder 

 feet applied to the ground. 



9. TALPA Incisors six above and eight below, nearly 



equal: tusks large: grinders seven above and six below 

 on each side : body very thick : fore feet short and broad, 

 formed for digging : tail short : no external ears : eyes 

 very minute. 



