72 PHYSIOLOGICAL SERIES. 



B. 111. The 2nd to the 9th dorsal vertebrse of a Fox-Squirrel 

 (Sciurus ludovicianus], with the articular extremities of the 

 corresponding ribs. The dorsal arches have been removed 

 to show a transverse ligament passing between each pair of 

 ribs, from head to head, on the dorsal surface of the inter- 

 vertebral disc. The ligaments (behind which a black bristle 

 has been placed) are only present between the heads of the 

 third to the ninth pairs of ribs. 



B. 112. A dorsal vertebra, and the articular extremities of four 

 ribs of a Horse (Equus caballus). 



These are attached by capsular ligaments to the angles of 

 the body of the vertebra ; they have also a strong transverse 

 ligament which passes from the head of one rib, dorsally to 

 the intervertebral substance, to the head of the opposite rib; 

 thus connecting them firmly to each other, and to the 

 vertebra. 0. C. 257. Hunterian. 



B. 113. Centrum of a dorsal vertebra of a Tapir (Tapirus terres- 

 tris) with the heads of the corresponding pair of ribs, 

 showing a similar transverse ligament. 



B. 114. Portions of four dorsal vertebrae of Sheep (Ovis aries) 

 with extremities of ribs attached, showing the strong trans- 

 verse ligament that unites the heads of the ribs. 



Presented ly P. D. Coyhill, Esq. 



B. 115. One mid-dorsal, and two last dorsal vertebrse, also articu- 

 lar ends of ribs, showing transverse ligament uniting their 

 heads. From a Seal (Phoca vitulina), seven days old. 



The ligaments proper to each pair of ribs are two in 

 number, they traverse respectively the dorsal and ventral 

 surfaces of the intervertebral disc. 



Presented by the Zoological Society. 



B. 116. The 7th to llth dorsal vertebrae of a Dog ( Canis famili- 

 am), with the heads of the corresponding ribs attached. 

 The neural arches have been removed to show four stout 

 transverse ligaments. They are only present between the 

 heads of the seventh to the tenth pairs of ribs. 



