Chapter IV

PORCUPINES--CHINCHILLAS--AGOUTIS--CAVIES--HARES AND
RABBITS--PIKAS.

HYSTRICIDÆ, THE PORCUPINES--Conversion of Hairs into
Spines--Skull--Dentition--Tail--Sub-families--The
True Porcupines--The Tree Porcupines--THE COMMON
PORCUPINE--Distribution--Description--The Crest of
Bristles--Nature of the Spines--Habits--Young--Flesh--On
the Defensive--Other Species--Species
of Tree Porcupines--THE COUENDOU--THE
COUIY--Description--Habits--THE URSON, OR CANADA
PORCUPINE--Description--Habits--Food--CHINCHILLIDÆ, THE
CHINCHILLAS--Characteristics--THE VISCACHA--Description--Life
on the Pampas--Their Burrows--Habits--The Chinchillas
of the Andes--THE CHINCHILLA--THE SHORT-TAILED
CHINCHILLA--CUVIER’S CHINCHILLA--THE PALE-FOOTED
CHINCHILLA--DASYPROCTIDÆ, THE AGOUTIS--Characters--THE
AGOUTI--Distribution--Appearance--Habits--AZARA’S
AGOUTI--THE ACOUCHY--THE
PACA--Appearance--Distribution--Habits--DINOMYIDÆ--Founded
for a Single Species--Description--Rarity--CAVIIDÆ,
THE CAVIES--Characteristics--THE RESTLESS
CAVY--Appearance--Habits--The Guinea-Pig
Controversy--THE BOLIVIAN CAVY--THE ROCK CAVY--THE
SOUTHERN CAVY--THE PATAGONIAN CAVY, OR MARA--Peculiar
Features--Its Burrows--Mode of Running--THE
CAPYBARA--Its Teeth--Where Found--Habits--THE
DOUBLE-TOOTHED RODENTS--Characteristics--LEPORIDÆ,
THE HARES AND RABBITS--Structural
Peculiarities--Distribution--Disposition--THE
COMMON HARE--Hind Legs--Speed--Its “Doubles”--Other
Artifices--Its “Form”--Habits--Food--Pet Hares--THE
RABBIT--Distribution--Habits--Domesticated--THE
MOUNTAIN HARE--LAGOMYIDÆ, THE
PIKAS--Characteristics--Distribution--THE ALPINE PIKA--THE
ROCKY MOUNTAIN PIKA 133

CHAPTER V.

FOSSIL RODENTIA.

Families of Rodents represented by Fossil
Remains--State of the “Record of the Rocks”--THE
SCIURIDÆ--Sciurine Genera now Extinct--No Fossil
ANOMALURIDÆ and HAPLODONTIDÆ--ISCHYROMYIDÆ--_Pseudotomus
hians_--_Gymnoptychus_--CASTORIDÆ--Mr.
Allen’s CASTOROIDIDÆ--THE MYOXIDÆ--No Fossil
LOPHIOMYIDÆ--THE MURIDÆ--THE SPALACIDÆ--THE
GEOMYIDÆ--THE DIPODIDÆ--THE THERIDOMYIDÆ--THE
OCTODONTIDÆ--THE HYSTRICIDÆ--THE CHINCHILLIDÆ--THE
DASYPROCTIDÆ--THE CAVIIDÆ--THE LEPORIDÆ--THE
LAGOMYIDÆ--_Mesotherium cristatum_--Difficulties
concerning it--Mr. Alston’s Suggestion--THE
HEBETIDENTATA--Teeth--Skull--Skeleton--Conclusions regarding
it--Table of Rodent Families--Concluding Remarks 151

ORDER EDENTATA, OR BRUTA (ANIMALS WITHOUT FRONT TEETH).