xvi LIST OF ILLUSTRATIONS. 



FIG. PAGE 



159. Spiral valve of skate. (T.J.PARKER), . . .487 



160. Upper part of the dorsal aorta in the skate. (MONRO), . 488 



161. Heart and adjacent vessels of skate. (MoNRO), . . 489 



162. Urinogenital organs of male skate, . . . 491 



163. Urinogenital organs of female skate. (MoNRO), . . 492 



164. Elasmobranch development. (BALFOUR), . . 494 



165. External characters of a Teleostean a carp. (LEUNis), . 496 



1 66. Caudal vertebra of haddock, .... 497 



167. Disarticulated skull of cod, '. . . . 498 



1 68. Pectoral girdle and fin of cod, .... 499 



169. Diagram of Teleostean circulation. (NuHN), . . 501 



170. Young skate. (BEARD), ..... 506 



171. Outline of Acanthodes sulcatus. (TRAQUAIR), . . 507 



172. Pterichthys milleri. (TRAQUAIR), . . . 509 



173. Skeleton of Ceratodus fin. (GEGENBAUR), . . 513 



174. Head region of Protopterus. (W.N.PARKER), . . 514 



175. Vertebral column and pelvic girdle of bull frog, . . 532 



176. Skull of frog upper and lower surface. (W. K. PARKER), 533 



177. Pectoral girdle of frog. (EcKER), .... 535 



178. Side view of frog's pelvis. (ECKER), . . . 536 



179. Brain of frog. (ECKER), ..... 537 



180. Nervous system of frog. (ECKER), . . . 538 



1 8 1. Arterial system of frog. (EcKER), . . . 542 



182. Venous system of frog. (ECKER), .... 544 



183. Urinogenital system of male frog. ( ECKER), . . 548 



184. Urinogenital system of female frog. (ECKER), . . 548 



185. Division of frog's ovum. (EcKER), . . . 550 



186. Gastrula stage of newt. (HERTWIG), . . . 551 



187. Dissection of tadpole. (MILNES MARSHALL and BLES), . 552 



188. Life history of frog. (BREHM), .... 554 



189. Gecilian (Ichthyophis] with eggs. (SARASIN), . . 557 



190. External appearance of tortoise, . . . 563 



191. Carapace of tortoise, . . . . 564 



192. Internal view of skeleton of turtle, . . . 565 



193. Dissection of Chelonian heart. (HUXLEY), . . 566 



194. Heart and associated vessels of tortoise. (NuHN), . 567 



195. Hatteria or Sphenodon. (HAYEK), . . . 568 



196. Side view of skull of Lacerta. (W.K.PARKER), . 572 



197. Heart and associated vessels of lizard. (NuHN), . 574 



198. Lung of Chamaleo vulgaris, showing air sacs. (WlEDER- 



SHEIM), ....... 576 



199. Snake's head. (NuHN), ..... 579 



