260 DR. J. E. GRAY ON THE SKULLS OF THE FELID.«. [Mar. 14, 



no one could make a mistake as to what it was, as the teeth are all 

 those of the Cats (Felidce). 



The skulls of species of Felis which have the same system of 

 colouring are not always alike : thus the skulls of Felis uncia, F. 

 marmorafa, and F. macrocelis, of Felis viverrina, F. benyalensis, 

 and F. nepalensis, and of F. pardina and F. macroura are very 

 diiferent in form and structure. On the other hand, the skulls of 

 the Lion, the Tiger, the Leopard, and the Jaguar are nearly similar 

 in form and teeth, and chiefly to be distinguished by their size and 

 other slight characters. 



Keyserling and Blasius have pointed out the diifereuces in the 

 skulls of the Wild Cat and the Lynx of Europe. The characters 

 mentioned are common to most of the species of the genera Felis 

 and Lyncus ; but Felis marmorata has a skull like that of the 

 Lynxes ; and the Chaus group, which have the pencilled ears of the 

 Lynxes, but not their long legs, have a skull like that of the Do- 

 mestic Cat. 



The Felis macrocelis has very long, rather compressed canine 

 teeth in the upper and lower jaws. Its skull presents the nearest 

 approach to those of the fossil Cats with very long sharp-edged ca- 

 nines, such as Felis cultridens of England, Germany, France, and 

 Italy, F. megatherion and F. smilodon of Brazil. The latter has 

 exceedingly long sword-like canines in the upper jaw. These animals 

 form the genera Machairodus and Agnotherium of Kaup (see Blain- 

 ville, Osteographie, Felis, t. 17 & 20). 



In most Felidce the orbits are furnished with an imperfect bony 

 ring ; in F. viverrina, F. subi-ugosa, F. planiceps, and some other 

 spotted Cats these orbits are complete even at an early age. 



The Domestic Cat has nocturnal eyes, with an elongated erect 

 pupil, and this has been generally given as the character of the 

 entire genus ; but the Lion, Tiger, Leopard, and some of the other 

 larger species have a round pupil, and do not, under any circum- 

 stances, ever contract their eyes into an erect linear shape ; so they 

 may be called diurnal eyes. 



The Domestic Cat, and the species of the genus that are known 

 to have nocturnal eyes with linear erect pupils when contracted, have 

 a very large eyeball and large orbits in the skull, while the eyeball 

 and orbit of the skulls of the Lion and other Cats, which are known 

 to have diurnal eyes, have a moderate-sized eyeball and orbit to 

 the skulls. 



Observing that the Cats, which are well known to have vertical 

 pupils, have large eyeballs and orbits in the skulls, I have taken it 

 for granted that all Cats which have large orbits in the skull have 

 vertical pupils. This is important, as we can observe the size of the 

 orbit in museums, while the form of the pupil can only be observed 

 in the living animal. The animals which have nocturnal eyes, gene- 

 rally have short small faces to the skulls ; but the Felis viverrina, 

 which certainly has nocturnal eyes, has a rather elongated nose to 

 the skull. 



As regards the form of the pupil in the Felidce there is a great 



