764 report— 1884. 



pre-sacral vertebrae hollow ; each sacral vertebra supports its own transverse pro- 

 cess. Fore and hind limbs nearly equal ; limb bones solid. Feet plantigrade, un- 

 gulate ; five digits in manus and in pes ; second row of carpal and tarsal bones 

 unossified. Sternal bones parial. Pubes projecting in front, and united distally by 

 cartilage ; no post-pubis. 



1. Family Atlantosauridce. A pituitary canal. Ischia directed downward, 

 with expanded extremities meeting on median line. Sacrum hollow. Anterior 

 caudals with lateral cavities. 



Genera : Atlaniosaurus, Apatosaurus, Brontosaurus. 



2. Family JDiplodocidee. Dentition weak. Brain inclined backward. Large 

 pituitary fossa. Two antorbital openings. Ischia with straight shaft, not expanded 

 distally, directed downward and backward, with ends meeting on median line. 

 Caudals deeply excavated below. Chevrons with both anterior and posterior 

 branches. 



Genus : Diplodocus. 



3. Family Morosauridcc. Small pituitary fossa. Ischia slender, with twisted 

 shaft, directed backward, and sides meeting on median line. Sacral vertebrae solid.' 

 Anterior caudals solid. 



Genus : Morosaurus. 



European forms of this order : Bot/iriospondylus, Cetiosaurus, Chondrosteo- 

 saurus, Eucamerotus, Ornithopsis, Pelorosaurus. 



II. Order Stegosatjkia (Plated Lizard). Herbivorous. Feet plantigrade, 

 ungulate ; five digits in manus and in pes ; second row of carpals unossified. Pubes 

 projecting free in front ; post-pubis present. Fore limbs small ; locomotion 

 mainly on hind limbs. Cervical ribs free. Vertebras and limb bones solid. 

 Osseous dermal armour. 



1. Family Stegosauridee. Vertebrae bi-concave. Neural canal in sacrum ex- 

 panded into large chamber ; ischia directed backward, with sides meeting on 

 median line. Astragalus coossified with tibia ; metapodials very short. 



Genera: Stegosaurus (Hypsirhophus), Diracodon, and in Europe Omosaurus. 



2. Family Scelidosduridce. Astragalus not coossified with tibia; metatarsals 

 elongated ; four functional digits in pes. Known forms all European. 



Genera : Scelidosaurus, AcantJwpholis, Cratceomus, Hylceosaurus, Polacanthus. 



III. Order Orniihofoda (Bird-foot). Premaxillaries edentulous in front. A 

 premandibular bone. Herbivorous. Feet digitigrade, five functional digits in 

 manus and three in pes. Pubes projecting free in front ; post-pubis present. 

 Vertebrae solid. Cervical ribs free. Fore limbs small ; limb bones hollow. 



1. Family Camptosauridce. Clavicles wanting ; post-pubis complete. 

 Genera: Camptosaunis, Laosaurus, Nanosaurus; and in Europe Hypsilophodon. 



2. Family Iyuanodontidce. Premaxillaries edentulous. Post-pubis incomplete. 

 Known forms ail European. 



Genera : Iguanodon, Vectisaurus. 



3. Family Hadrosaurida. Teeth in several rows, forming with use a tesselated 

 grinding surface. Anterior vertebrae opisthoccelian. 



Genera : Hadrosaurus (Diclonius), ? Agathaumas, Cionodon. 



IV. Order Thekopoda (Beast-foot). Carnivorous. Premaxillary bones with 

 teeth. Anterior nares at end of skull. Large antorbital opening. Vertebras 

 more or less hollow. Limb bones hollow. Feet digitigrade ; digits with prehensile 

 claws. Pubes projecting downward, with distal ends coossified. 



1. Family Megalosauridce. Anterior vertebrae convexo-concave ; remaining 

 vertebrae bi-concave. Pubes slender. Astragalus with ascending process. 



Genera : Megalosaurus (Poikilopleuron), Allosaurns, Ccelosaurus, Creosaurus, 

 Dryptosaurus (Lcelaps). 



2. Family Labrosauridce. Lower jaws edentulous in front. Cervical and 

 dorsal vertebrae convexo-concave. Pubes slender, with anterior margins united. 

 Astragalus with ascending process. 



Genus: Labrosaurus. 



3. Family Zanclodcmtidce, Vertebrae bi-concave. Pubes broad elongate plates, 



