FELIS SPELyEA. 37 



])lexus" proper, wliicli lias the same insertion as the preceding, and passes backwards to 

 the diapophyses of the cervical vertebras, and thence to the three anterior dorsals. The 

 great, lesser, and middle recti posteriores of the head underlie these two muscles ; their 

 insertions extending nearly to the upper edge of the foramen magnum, and their origins 

 being in the atlas and axis. These five muscles serve to lift up, and to a certain extent 

 to rotate, the head. Their points of insertion are therefore necessarily of great strength 

 in the larger and more poweifiil Feles. In Felis spelaa they are not more aiassive propor- 

 tionally to the size of the animal than in the living tigers and lions. 



The great splenius muscle springs from the " cervical ligament," and an aponeurosis 

 which connects it with the last cervical and first five dorsals, and ends in a short strong 

 tendon which is inserted into the occipital bone immediately behind the lambdoid suture. 

 Its enormous size and strength in Felis fspelaa is seen by the large fossae for its insertion 

 ill n. IX, fig. 1. It takes part in the same movement as the preceding five muscles. 

 The " trachelo-raastoid " of Douglas rises from five tendinous roots attached severally to 

 the last four ccrvicals and the first dorsal, and passes in the form of a long thin band 

 along the side of the neck to its insertion on the paroccipital. Near it is inserted the 

 " rectus lateralis," which has its origin on the ala of the atlas. The " superior obliquus" 

 of the head has nearly the same direction as' the last, but passes within it to be inserted 

 on the surface of the paroccipitals in the upper part of the condyloid fossa, at the point 

 Avhere they join the exoccipitals. 



These three muscles, together with the splenius, bend the head from side to side. 

 The great size of the lateral alae of the atlas stands in direct relation to the development 

 of these muscles, in animals that shake and worry their j)rey, such as lion, tiger, and 

 Felis spclcca. 



M. de Blainville^ states that the occipital crest is prolonged further backwards in the 

 tiger than in the lion, a point which we have remarked to be by no means of characteristic 

 value, and that the condyles are more detached in the former than in the latter animal. 

 Wc have frequently found the converse of this latter statement to be true. He also 

 writes that in these two points the plaster cast of Count Miinster's specimen of Felis 

 ^jjclacc' agrees with tiger and differs from lion. We are unable to lay hold of any 

 character in the occipital bone that would differentiate lion from tiger or from Felis 

 xpelaa. 



§ 4. Basisphenoid (PI. VIII, No. 5). — The basisphenoid is articulated to the 

 prcsphenoid by a transverse suture, which is clearly visible even in animals of considerable 

 age. It is much wider though about the same length as this latter bone. The form of 

 the inferior or guttural surface exposed in the perfect skull is roughly triangular, the apex 

 of the triangle being cut off by the presphenoidal suture, and the base being formed by 



1 < 



Ost. Felis,' p. 28. - ' Ost. Fcli^,' p. 108. 



