Crocodilia. 



Wall-case, 

 No. 2. 



Table-cases, 

 Nos. 10 to 11. 



Table-case, 

 No. 12. 



Belodon. 



Wall-case, 

 No. 2. 



Table-case, 

 No. 13. 



6 Crocodiles — Geosaurus. 



diles. Professor Owen lias constituted two groups, based on 

 those modifications of the vertebrae. The Crocodiles belong to 

 the Procoelian section (vertebrae concave in front), and are 

 divided into a hrevirostrine, or short-snouted section, containing 

 the Alligator, the Crocodile, and the Tertiai*y genufiDlpIocynodon; 

 and a lofigirostrine, or long-snouted section, embracing the 

 Garlals, Tomistoma, Tho7-acosanrus, and lihamphosuchus. 



The Aniphiccelian section (vertebrce concave at both ends), 

 embraces HylfHocliampsa, also a second brevirostrine section 

 including TJieriosuchns, Goniopholis, Nannosuchus, and Oivenia- 

 suchus, and a second longirosti'ine section for Pholulosaurus and 

 Petrosuchus, all from the Wealden and Purbeck beds. 



The older secondary forms belong to the Amphiccelian section 

 as Dacosmirus, Metriorhynchns, Teleidosaurus, Machimosaurus, 

 Pelagosaurus, Steneosaurus, and Teleosmirus. The earliest of the 

 Crocodilian reptiles is named Belodon (Fig. 8) ; it had long 

 and pointed slightly-curved teeth, longitudinally grooved, and 



Fio. 7. — Crocodilus Spenca-i (Bucklaiul). Upper view of skull restored, from the 

 London Clay of Sheppey (about i nat. size). 



Wall-case, 

 No. 2. 



Qeosaurus. 



elongated jaws like the modern Garials ; the other, named 

 Stagonolepis, resembled the existing Caimans, but with an elon- 

 gated skull like the Garials; the body Avas covered by bony 

 scutes. Both these reptiles are from the Trias, the former from 

 Stuttgart, Germany; the latter from Elgin, Scotland. In the 

 Oolitic and Liassic series the old type of long and slender- 

 jawed Teleosaurs and Steneosaurs (Figs. 9 and 11), with 

 strong bony scutes, was abundantly represented. 



Here are exhibited the type specimens of Geosaurus, 

 from the lithographic stone (Upper Oolite) of Solenhofen, 

 Bavaria. Baron Cuvier inferred, from the form and structure 

 of its skull, that Geosaurus held an intermediate place between 

 the crocodiles and the monitors, but was more nearly related 

 to the latter. The orbits are large and the eyes were protected 

 by bony sclerotic plates, like those of Ichthyosaurus. It had 



