In the centre of this gallery is placed a large portion of the skeleton of a gigantic Dinosaur (_Cetiosaurus leedsi_) from the Upper Jurassic Oxford Clay near Peterborough. It is nearly allied to the North American _Diplodocus_, of which, as mentioned on page 57, the model of a complete skeleton is exhibited in the recent Reptile Gallery. Both _Cetiosaurus_ and _Diplodocus_ resemble _Brontosaurus_ (fig. 51) in the extremely small size of the skull. Another central case contains an actual skull and other remains of the American Cretaceous horned Dinosaur _Triceratops_ (see page 57), and in wall-case 8 is placed a plaster cast of the skull of the contemporary _Tyrannosaurus_, the largest known carnivorous Dinosaur. At the eastern end of the gallery are the Pterosauria or Ornithosauria, commonly called Pterodactyles or Flying Reptiles. Their most gigantic representatives were the species of _Pteranodon_ from the Upper Cretaceous of Kansas (fig. 53). At the west end is the nearly complete skeleton of _Pariasaurus_ (fig. 52) from the Karoo formation (Trias) of South Africa. It occurs also in Russia, and belongs to a primitive section of the Theromorphs, or Anomodonts, which include the ancestors of Mammals. [Illustration: FIG. 51.--SKELETON OF _Brontosaurus ingens_, A FOUR-FOOTED DINOSAUR FROM THE JURASSIC FORMATION OF N. AMERICA. 1/150 natural size.] [Illustration: FIG. 52.--SKELETON OF PARIASAURUS. About 1/14th natural size.] [Sidenote: Extinct Fishes.] Of the galleries running northwards from the Fossil Reptile gallery, the one nearest to the central hall is used for the display of the Fossil Fishes, many belonging to groups now extinct. Perhaps the most remarkable of all, and certainly most unlike existing forms, are the armoured Devonian Fishes known as _Cephalaspis_, _Pterichthys_ (fig. 54), etc. The well-preserved fishes from the Chalk are especially noteworthy, and a specimen of _Portheus_ in a central case, 14 feet in length, is one of the largest bony fishes known. [Illustration: FIG. 53.--A GIANT PTERODACTYLE (_Pteranodon occidentalis_) FROM THE CRETACEOUS OF KANSAS. (Original span about 18 feet.) Compare the wing, which is supported by the outermost finger, with that of the Bat in Fig. 8. ] [Sidenote: Extinct Invertebrates and Plants.]