LIST OF ILLUSTRATIONS. XV 



156. Diagram of the structure of Sepia (Pelseneer) . . 360 



157. Diagram of circulatory and excretory systems in a Decapod, 



like Sepia (Pelseneer) . 362 



158. Common Buckie, Buccinum undatum . . 364 



159. Bivalve, Panopa-a noi~vegica, showing siphons . . 365 



160. Nudibranch, Dendronotus arborescens, showing dorsal out- 



growths forming adaptive gills .... 366 



161. Ventral surface of Patella vulgata (Forbes and Hanley) . 366 



162. Chiton (Pretre) 370 



163. Dorsal view of nervous system of Chiton (Pelseneer) 370 



164. Proneomenia. Nervous system (Hubrecht) . 370 



165. Anatomy of Chiton ... 371 



166. Stages in Molluscan development . . 376 



167. Section of shell of Nautilus (Lendenfeld) . . 382 



168. The Pearly Nautilus, Nautiltis pompilius (Owen) 383 



169. Male of Balanoglossus kowalevskii (Bateson) . . 388 



170. Transverse section through gill-slit region of Ptychodera 



mimtta (Sprengel) . . . . 390 



171. Development of Balanoglossus (Bateson) . 391 



172. Tornaria larva, from the side (Sprengel) . 392 



173. Dissection of Ascidian (Herdman) . 398 



174. Do. Do. .... 401 



175. Young embryo of Ascidian, Clavelina (Van Beneden and 



Julin) ...... 403 



176. Embryo of Clavelina (Seeliger) . . . 404 

 176A. " Nurse" of Doliohim mulleri (Uljanin) . 407 

 1 76B. Sexual individual of Doliohim mulleri (Uljanin) . . 407 

 176c. Anatomy of Appendicularia (Herdman) . 408 



177. Lateral view of Amphioxus (Ray Lankester) . . 412 



178. Transverse section through pharyngeal region of Amphioxus 



(Ray Lankester) . . . . . . 413 



179. Development of atrial chamber in Amphioxus 416 

 180 and 181. The nephridia of Amphioxus (Boveri) . . 418 



182. Early stages in the development of Amphioxus (Hatschek) . 421 



183. Sections through embryos of Amphioxus, to illustrate de- 



velopment of body cavity . ... 422 



184. Transverse section through an Elasmobranch embryo (dia- 



grammatic) (Ziegler) 430 



185 and 186. Ideal fore- and hind-limb (Gegenbaur) . . 437 



187. Longitudinal section of brain of young dog-fish (diagram- 



matic) (Gaskell) . . . 439 



188. Origin of pineal body (Beard) 440 



189. Diagram of the parts of the brain in Vertebrates (Gaskell) . 441 



190. Diagrammatic section of spinal cord . . . 445 



191. Diagram of the eye . 449 



192. Development of the eye (Balfour and Hertwig) . . . 450 



193. Origin of lungs, liver, and pancreas in the chick (Gcette) 454 



194. Transverse section through a Teleostean embryo (diagram- 



matic) (Ziegler) . 456 



195. Diagram of circulation (Leunis) . . 459 



