FEB., 1912. MAMMALS OF ILLINOIS AND WISCONSIN CORY. 491 



Pentadactylous With five fingers or toes. 



Placenta The organ by which the fetus of the higher mammals is nourished. 



It is connected with the fetus on one side by the umbilical cord and on the 



other is attached to the walls of the uterus, from which it is detached at birth. 

 Plantar tubercles Wart-like excrescences on under surface of foot. 

 Plantigrade Walking on practically the whole sole of the foot. 

 Pollex The thumb or first toe of front foot. 

 Postorbital Behind the eye. 



Premolars Teeth in side of jaw between the molars and the canine. 

 Ramus, pi. rami The ascending part of the lower jaw at the posterior end. 

 Rostrum The part of the skull in front of the eyes, made up of the nasal and part 



of the premaxillary and maxillary bones; practically, the snout. 

 Sagittal crest A bony ridge along the middle upper surface of the brain case in 



some mammals. 



Sectorial Adapted for cutting; usually used to describe certain teeth. 

 Septum A partition. 

 Skin Consists of two layers: an outer one termed the epidermis or cuticle (which 



has no blood vessels), beneath which is a second layer or true skin, variously 



called dermis, corium or cutis vera, which is abundantly supplied with nerves and 



blood-vessels. The skin covers the outer surface of the body and continues in a 



softer and somewhat modified form (termed mucous membrane) as a lining for 



the internal passages, such as the digestive and urogenital tracts. 

 Squamate Scaly or covered with scales. 

 Squamosal bone See chart, p. n. Forms part of the temporal bone in man; 



what answers to the squamous portion in man is called the squamosal in lower 



animals. 



Squamous Covered with scales, scaly or resembling a scale. 

 Sulcate Grooved. 



Supraorbital Expansion of bone above the eye, noticeable in the Hares and Rabbits. 

 Suture Line of union or point of junction of two bones, which ultimately unite 



and become immovable. 



Synonym One of two or more names for one and the same thing. 

 Tactile Pertaining to the sense of touch. 

 Tail vertebrae or caudal vertebras See page 10. 

 Tarsus Bones forming the ankle joint. See chart, p. 10. 

 Tautonym Binomial name, having generic and specific names alike. 

 Terrestrial Living on the ground. 



Thoracic Used here as pertaining to the chest or thorax. 

 True skin Inner portion of the skin known as dermis or corium or cutis vera. 

 Tooth row Continuous row of teeth on side of jaw posterior to the canine (most 



commonly used in describing Rodents). 

 Topotype A specimen collected in the exact locality where the original type was 



obtained. 

 Tragus, pi. tragi An erect cartilaginous process in the conch or external ear of a 



bat. 



Trochanter One of the bony processes of the thigh bone. 

 Truncate Blunt. 

 Tuberculate Having tubercles or small projections; commonly used in this work 



in describing teeth. 

 Type [of genus] The species which was originally designated or later selected 



in conformity with the rules of zoological nomenclature to typify a genus. 



