392 MR. ST. GEORGE MIVART AND DR. J. MURIE [Julie 26, 



tion is probably represented by what has much the appearance of 

 the most anterior (upper) part of the longus colli. This arises by 

 tendon and muscular fibre from the transverse processes of the 

 second and third cervical vertebrae, and is inserted partly into the 

 hypapophysis of the atlas, and partly into the basis cranii in front of 

 the tendon of origin of the scalenus anticus. 



It is the same and strongly developed in the Guinea-pig. 



The rectus capitis anticus minor is more easily defined than the 

 preceding muscle. Its attachments of origin are the transverse pro- 

 cess of the atlas and part of the body of that vertebra ; it is inserted 

 into the basis cranii, immediately behind the origin of the levator 

 claviculae, with which, moreover, it is more or less fused. 



It is alike in the Guinea-pig. 



The rectus lateralis is large and fleshy ; it passes, as usual, from 

 the transverse process of the atlas to the skull. 



Longus colli. If we consider the muscular belly described as the 

 rectus capitis anticus major to be really such, and not a part of the 

 muscle now under consideration, then the longus colli extends be- 

 tween the transverse processes and bodies of the vertebrae from the 

 seventh dorsal to the atlas — no fibres, however, being attached to the 

 transverse processes of the dorsal or first three cervical vertebrae. 



It is exactly the same in the Guinea-pig. 



Scalenus anticus. This presents very interesting characters, both 

 as to its form and origin. It is a very long thin band of muscle, 

 tendinous on its lower surface, and arising by a strong tendon from 

 the basis cranii, immediately in front of the origin of the levator cla- 

 viculae, but rather nearer the middle line. It is inserted upon the 

 anterior margin of the first rib, between the subclavian vein and ar- 

 tery, and altogether beneath (in front of) the bronchial plexus. 



Meckel* says that this muscle is absent in the Agouti. 



This muscle is the same in the Guinea-pig ; and here the tendon 

 of origin from the basis cranii is very delicate. 



In the Hare this muscle seems to be wanting. 



The scalenus medius and s. posticus are one very large posteriorly 

 expanded and conjoined muscle in the Agouti. It arises from the 

 whole of the transverse processes of the cervical vertebrae, including 

 the atlas, and not, as Meckel f says, from only the last five. It is 

 inserted into the first five ribs. 



In the Guinea-pig it is very similar, and strongly developed. 



In the Hare there are two muscles, the external superficial one of 

 which arises from the transverse process of the fifth cervical vertebra 

 and is inserted into the three foremost ribs. The deeper and shorter 

 one arises from the transverse process of the sixth cervical vertebra, 

 and is inserted into the first rib, outside and superficial to the vessels 

 and nerves. 



Muscles of the Back and Abdomen. 



Panniculus carnosus. The very lean condition of Our specimen 

 permitted this muscle to be well seen in its entire extent (figs. 2 & 3, 

 * Op. cit. vol. vi. p. 157. t Loc. cit. 



