672 GLOSSARY 



Spine, (of the scapula) a bony ridge on the outside of the shoulder-blade ; 



(of the tibia) a single or double prominence from the upper end of the 



shin-bone ; (of a vertebra) the neural spine. 

 Squamosal, a bone forming the posterior side-wall of the cranium. 

 Sternal ribs, the inferior segments of the ribs, which articulate with the 



breast-bone. 

 Sternum, the breast-bone. 

 Stratum, a layer of bedded rock. 

 Subclass, primary division of class. 

 Subfamily, a group of related genera within the family. 

 Subgenus, a group of related species within the genus. 

 Suborder, primary division of order. 

 Subspecies, a definite subdivision of a species. 

 Suina, swine-like animals ; suborder of Artiodactyla. 

 Superfamily, a group of related families. 

 Superorder, a group of related orders. 

 Supinator ridge, a crest on the outer side, near the lower end of the humerus, 



for attachment of the supinator muscle. 

 Symphysis, the line of junction of the two halves of the lower jaw. 

 Synonym, a name improperly given to a genus or species already named.. 



tTseniodontia, an extinct order of clawed mammals. 



Tarsal, an element of the tarsus. 



Tarsus, the bones of the ankle-joint. 



Temporal muscle, a muscle of mastication attached to the side of the cra- 

 nium and the coronoid process of the lower jaw. 



Tertiary, the more ancient of the two Cenozoic periods. 



Thoracic vertebrae^, see Dorsal. 



Thorax, the bony framework of the chest. 



Tibia, the shin-bone, internal bone of the lower leg. 



fTillodontia, an extinct order of clawed mammals. 



fToxodonta, an extinct suborder of the fToxodontia. 



fTozodontia, an extinct order of hoofed mammals. 



fToxodonts, see fToxodonta. 



Tragulina, " Mouse Deer " ; suborder of Artiodactyla. 



Transverse processes, projections from the sides of a vertebra. 



Trapezium, internal bone in the lower row of the carpus ; supports the first 

 digit, or thumb. 



Trapezoid, second bone in the lower row of the carpus ; supports the second 

 digit, or index finger. 



Triassic, first of the three Mesozoic periods. 



fTriconodonta, an extinct suborder of Mesozoic Marsupials. 



fTrituberculata, an extinct order of Mesozoic mammals. 



Trochanter, a projection from the femur. 



