392 THE ANIMAL KINGDOM. 



as N. Australia, in Cuba and S. America ; the Alligators are confined to S. America 

 and southern part of N. America. All existing Crocodiles have procoelus vertebrae, 

 and appear first in the Greensand ; the extinct Teleosauria with amphicoelous or 

 partly opisthocoelous (Steneosaurus) vertebrae come from the Lias, Kimmeridge 

 Clay, Inferior and Bath Oolite. The genus Belodon is Triassic. 



In addition to the four groups of living Reptilia, there are a number of extinct 

 groups. The Plesiosauria and Ichthyosauria are marine forms ranging, the former 

 from the Trias, the latter from the Lias, to the Chalk. Their skin appears to have 

 been naked. Ichthyosaurus is believed to have had a vertical tail fin, its intestine 

 had a spiral valve, and some of the species were viviparous (Brit. Ass. Reports, 1880, 

 p. 68). The neck is long in the former group ; in the latter short. Both have the 

 limbs modified into paddles. The Deinosauria are strictly terrestrial, but some of 

 them, e.g. Iguanodon, appear to have frequented marshy ground or swamps. The 

 group (sub-class, Marsh) comprises a large assemblage of herbivorous and car- 

 nivorous forms. Two of the sub-divisions (Stegosauria and Ornithopodd] show ornithic 

 characters especially in the hind-limb. The group extends from Triassic strata to 

 the Chalk (Maestricht beds in Europe). Some of the genera are gigantic in size. 

 A very large number have been discovered in America. The Anomodontia are 

 terrestrial forms, found in rocks of Triassic age in S. Africa, India, and the Ural 

 Mountains. A portion of a skull has recently been obtained from a New Red 

 Sandstone quarry near Elgin. Dicynodon and the Theriodontia (Owen, Journal 

 Geol. Soc. 1876), &c., belong to this group. 



Finally, there is a remarkable order of Flying Reptilia the Pterodactyla, Ptero- 

 sauria, or Ornithosauria, found in strata from the Lias to the Chalk inclusively. 

 The fifth finger is immensely elongated, and supports the wing membrane. The 

 toothless American genus Pteranodon is of immense size, fifteen feet from the tip 

 of one wing to the tip of the other. Accounts of the anatomy of the Plesiosauria, 

 Ichthyosauria, Ornithoscelida (= Deinosauria in part), Dicynodontia (Anomodontia in 

 part), and the Pterosauria will be found in Huxley, Anatomy of Vertebrated 

 Animals, 1871, or in Quenstedt's Handbuch der Petrefactenkunde, ed. 3, 1882-83. 

 Some additional memoirs are noted below. 



Reptilia, Hoffmann, Bronn's Klass. und Ordn. des Thierreichs, vi. Abth. 3 (in 

 progress). 



Chelonia, Strauch. Mem. de 1'Acad. Imp. St. Pe*tersbourg (7), viii. 1865. 

 Development of Green Turtle, W. K. Parker, Challenger Reports, i. 1880. Cara- 

 pace, &c. ; cervical ribs, &c., Hoffmann, Niederland. Archiv f. Zool. iv. 1877-78; 

 v. 1879-82. Peritoneal canals, see Bridge, cited p. 279, ante. 



Lacertilia. Anatomy of Lizard,^. J. Parker, Zootomy, London, 1884. Skull, 

 W. K. Parker, Ph. Tr. 170, 1879. Chamaeleon ; skull, Id. Tr. Z. S. xi; changes of 

 colour in do., Krukenberg, Vergleich. Physiol. Studien, i. Abth. 3, 1880. Amphis- 

 baena, Bedriaga, A. N. 50. i, 1884; Smalian, Z. W. Z. xlii. 1885. 



Ophidia, see p. 72 and 73, ante. 



Crocodilia, Strauch. Me*m. de 1'Acad. Imp. St. Petersbourg (7), x. 1866. 

 Skull, development of, W. K. Parker, Tr. Z. S. xi. 



The fossil groups are treated principally in the following. Plesiosauria and 

 Ichthyosauria, Owen, Fossil Reptiles of Liassic Formations, Palaeontographical 

 Society; Id. Palaeontology, ed. 2, Edinburgh, 1861 ; limbs, see Baur, Z. A. ix. 

 1886. Anomodontia, Owen, Catalogue of S. African fossils in British Museum, 



