12 THE BRITISH MAMMALS : ORDERS, FAMILIES, ETC. 



Two upper incisors ; one lower incisor 

 Head crested Cystophora, 34. 



Three upper incisors ; two lower incisors 

 Head flattened Halichcerus, 33. 

 Head rounded Phoca, 30 to 32. 



Four hind toes 



2. (Felidae) 



Muzzle short Fells, 21. 



3. (Canidae) 



Muzzle long Vulpes, 22. 



Five hind toes 



4. (Mustelidae) 



Toes webbed Lutra, 29. 



Toes not webbed 

 Tail long Mustela, 23. 



Tail short- 

 Fore claws longer than hind claws Meles, 28. 

 Fore claws not longer than hind claws Putorius, 

 24 to 27 



In the rodents the feet will also help us. The hares and rabbit 

 (Leporidae) have four toes on the hind feet and five on the others, 

 and in the only British genus (Lepus) the soles of the feet are hairy. 

 In the three other families represented there are five toes on each 

 foot, but the first toe of the fore feet is rudimentary. They can be 

 sorted out by their tails : the squirrel (Sciuridse) has the tail long 

 and bushy ; the dormouse (Myoxidae) has it long and hairy ; the mice 

 and rats (Muridae) have it long and scaly, and the voles belonging 

 to the same family have it short and hairy. 



Tabulating as before we have 



RODENTIA 



Hind feet with four toes ; fore feet with five toes. 



1. (Leporidae) 



Soles of feet hairy Lepus, 46 to 48. 

 Hind feet with five toes ; fore feet with first toe rudimentary. 



2. (Sciuridae) 



Tail long and bushy; premolars, two pairs in upper jaw, 

 one in lower jaw Sciurus, 35. 



3. (Myoxidas) 



Tail long and hairy; premolars, one pair in each jaw 

 Muscardinus, 36. 



4. (Muridae) 



Tail short, or long and scaly; premolars none . 

 Tail long and scaly Mus, 37 to 42. 

 fail short and hairy Microtus, 43 to 45. 



