CLASSIFICATION OF VERTEBRATA 42 



Dasypodidae. Neotropical. Eecent : 



Dasypus, Priodon, Tatusia, Chlamydophorus. Plistocene : 

 Hoplophorus, Glyptodon, etc. 



2. Order Trogontia, Haeckel. Terrestrial, plantigrade, 

 pentadactyle (unless the first digit is reduced as in some 

 Eodentia). 



Clavicles mostly strong. 



Tendency of the second pair of incisors to excessive, ro- 

 dential development, and gradual suppression of the first and 

 third pair of incisors. Canines reduced or lost. 



1. Sub-order TILLODONTIA, Marsh. Pentadactyle, with 

 claws. Dentition complete ; second incisor largest. 



Mandibular condyle transverse. 



Humerus with entepicondylar foramen. 



Femur with third trochanter. 



Lissencephalous. Eocene. 



Estlionycliidae. Esthonyx. Lower Eocene of North America 

 and England. 



Tillotheriidae. Tillotherium. Wyoming. 



Stylinodontidae. Stylinodon. North America and 

 Europe. 



2. Sub-order TYPOTHEKIA, Zittel. Digits -^-., One 



5 or 4 



pair of upper incisors enlarged. Molars prismatic, high, mostly 

 rootless. Mandibular condyles roundish. With entepicondy- 

 lar foramen, and with third trochanter. Tertiary. 



Protypotlieriidae. Protypotherium. Mid-Tertiary, Pata- 

 gonia. 



Typotheriidae. Typotherium, new Tertiary. Pachyrucos. 

 Tertiary, Patagonia. 



3. Sub-order KODENTIA, Vicq. d'Azyr. Digits jj^iT 

 Second pair of incisors much enlarged and rootless ; the others 

 much reduced or lost. Canines absent. Mandibular con- 

 dyle longitudinal. Clavicles weak or absent. 



Uterus bicornis. Placenta discoid, deciduous. Cosmo- 

 politan, few in Australia and Madagascar. About 900 recent 

 species. 



LAGOMORPHA, Brandt. Incisors ^; one small incisor is 

 placed behind the much enlarged second. Eibula articulating 



