xvi GENERAL INDEX. 



Page Sec. 



Vascular system . . . 153 406 



Hermaphroditism of Planarice 153 407 



Structure of generative apparatus in Planar i a tremellaris . . . 153 408 



NEMERTEAN HELMINTHOZOA 153 409 



Ciliated integument 154 410 



Alimentary apparatus 154 411 



Circulatory system .,..,... 155 413 



Reproductive organs 156 417 



CCELELMINTHA Ascaris lumbricoides, general history of 157 419 



Muscular parietes of the cavitary Helminthozoa 157 420 



Structure and arrangement of the muscular system 157 421 



Nervous system of Ascaris 158 422 



Digestive system . 158 423 



Caecal appendages to alimentary canal met with in some species . 159 424 



Nutritive appendages v.v 159 425 



In the Ccelelmintha the sexes are separate 159 426 



Structure of female sexual apparatus ........... 159 426 



Formation of the ova in the pvaria 160 427 



Sexual organs of male Ascaris 160 428 



Trichina spiralis 161 429 



CHAPTER VIII. 



ECHINODERMATA. 



ECHINODERMATA General view of the class 161 . 430 



CRINOID^E 162 . 433 



Structure of Encrinus 162 . 433 



Organization of fossil Encrinites 163 . 434 



ASTERIDJS '.' ".""*! ; . .". ' :Vw .'.'.- '... . 163 . 436 



Comatula 1 I I . 1 ."'".... 163 . 436 



Gorgonocephalus 164 . 436 



Ophiura , 165 . 437 



Asterias . . * 166 . 438 



Locomotive apparatus of Star-fish 166 . 439 



ECHINIDJS V. , ... 167 . 440 



Scutetta 167 . 440 



Echinus ' .- . . 168 . 441 



HOLOTHURIDJS '. 169 . 442 



Holothuria . . . .,!?.?.. t .;...,. ,.' 169 . 442 



FISTULARIDJS 169 . 443 



Fistularia .>.,. ;' . . . . . . . 170 . 443 



Anatomical structure of Asterias . . * ..:.-. .. ....,,,* ,j, ', ... . . 170 . 445 



External coriaceous integument 170 . 446 



Dermic secretions 171 . 447 



Tegumentary spines 171 . 448 



Pedicellariae 171 . 449 



Calcareous framework of skeleton 172 . 450 



Dorsal reticulations 172 . 451 



" Vertebral " plates 172 . 452 



Composition and arrangement of " vertebras " 172 . 453 



Ambulacra! apertures 172 . 453 



Ambulacra! grooves 172 . 453 



Ambulacra! suckers 172 . 454 



Mechanism of the ambulacra! suckers 172 . 454 



Peritoneal lining of visceral cavity ....... . .' .' . 175 . 457 



Alimentary system of Asterias 175 . 458 



Caecal appendages to the stomach . . . 175 . 459 



Functions of cnecal appendages 175 . 460 



Food of Star-fishes 177 . 465 



