GLOSSARY 667 



Deltoid crest, a ridge on the anterior face of the humerus for the attachment 



of the deltoid muscle. 

 Dental formula, an arithmetical expression of the numl:)er and kinds of teeth. 

 Dermoptera, Flying Lemur, order of placental mammals. 

 Deseado stage, terrestrial formation of Patagonia, probably Oligocene. 

 Didelphia, lower infraclass of the Eutheria. 

 Digit, a finger or toe. 



Diprotodonta, Kangaroos, etc., a suborder of Marsupials. 

 Dorsal vertebrae, those which carry ribs. 

 Duplicidentata, Hares and Rabbits, suborder of Rodentia. 



Edentata, Sloths, Anteaters, etc., an order of placental mammals. 



Edentates, see Edentata. 



fEmbrithopoda, an extinct order of elephant-like mammals. 



Embryo, young animal in early stages of development within the uterus. 



fEntelonychia, extinct suborder of the fToxodontia. 



Eocene, second of the five Tertiary epochs. 



Epicondylar foramen, perforation of the internal epicondyle for transmission 



of the ulnar nerve. 

 Epicondyle, a rough prominence on each end of the humeral trochlea. 

 Epiphysis, the ends of the long bones, which ossify separately and do not 



coalesce with the shaft until growth ceases. 

 Equus Beds, see Sheridan stage. 

 Eutheria, the higher subclass of mammals ; viviparous. 



Family, group of the third order in classification, tyi^ically containing several 



genera. 

 Fauna, the totality of animals of a given time or place. 

 Femur, the thigh-bone. 

 Fibula, the external bone of the lower leg. 

 Fissipedia, land-carnivores ; suborder of the Carnivora. 

 Flora, the totality of plants of a given time or place. 



Foetus, young animal in the later stages of development within the uterus. 

 Foramen, a perforation in a bone for the passage of a nerve or blood-vessel. 

 Foramen magnum, the opening in the occiput for the passage of the spinal 



cord to the brain. 

 Formation, a general term for a group of strata, laid down continuously and 



under uniform conditions. 

 Frontal, one of a pair of bones which form the anterior part of the cranial 



roof ; the forehead. 



Genus, group of the second order in classification, ty]Dically containing several 



species. 

 Glenoid cavity, (of the squamosal) the articular surface for the condyle of the 



lower jaw ; (of the scapula) the socket for the head of the humerus. 



