ii8 BRITISH MAMMALS 



finger of the fore limb (our thumb) is always shorter than the 

 others ; and this is generally the case with the first or innermost 

 toe in the feet. 



Family: CANID^. THE DOGS 



In some respects this group is the most generalised of the 

 existing Carnivora. In one genus [Otocyon)'^ (and occasionally, 

 as a sport, in the genus Canis) the number of teeth reaches to or 

 exceeds the typical mammalian forty-four because it includes one 

 or two extra pairs of molars. The caecum is always present, 

 in some species short, in others long, and rather curiously folded. 

 There is an alisphenoid canal,^ but the entipicondylar perforation 

 of the humerus (see p. 149) is wanting in existing dogs, though 

 present in extinct forms. No known dog is ever marked with 

 spots and stripes, as in the cats, civets, and some other Carnivora ; 

 but there is a slight tendency to black-and-white markings on 

 the face, characteristic also of the raccoons and badgers. 



Genus: LYCAON. THE HUNTING DOG 



This genus is scarcely separable from that which follows ; 

 but in Lycaon there are only four toes on each limb, as against 

 five on the fore feet and four visible toes on the hind limbs 

 in the typical dogs. The teeth of Lycaon are more massive 

 than those of the wolves. The fourth premolar in the lower 

 jaw has an extra cusp in front. The skull is somewhat shorter 

 and broader. The Hunting Dog is also distinguished by the 

 relative length of the intestines, and by the cartilage below the 

 tongue. The ears are long and somewhat rounded, and the tail 

 is bushy. The coloration is very peculiar. On a groundwork 



1 It is really a question whether Otocyon should still be included in the 

 family Canidce. Its osteological differences from the True Dogs are at least 

 of family rank. 



^ The alisphenoid canal, constantly referred to in the classification of the 

 Carnivora, is a short channel or tunnel in the alisphenoid bone, on the under 

 surface of the skull, near the origin of the palate. Through this perforation 

 passes the carotid artery. 



