xii LIST OF ILLUSTRATIONS 



FIG. PAGE 



843. Urolophus cruciatus 166 



844. Centrophorus calceus, dermal denticles 167 



845. Scymnus, spinal column 167 



846. Urolophus, skeleton 169 



847. Heptanchus, skull 170 



848. Torpedo-Ray, showing electric organ 172 



849. Cestracion galeatus, egg-case 176 



850. Pristiurus, section of blastoderm 177 



851. ,, formation of mesoderm 177 



852. Elasmobranch embryo, sections 178 



853. Scyllium canicula, embryo 179 



854. Ray, embryo 179 



855. Elasmobranch embryo with yolk-sac 180 



856. Scyllium canicula, head of embryo 181 



857. later stage . . . . .181 



858. Chimsera and Callorhynchus 183 



859. vertebral column 185 



860. skull 186 



861. Callorhynchus antarcticus, skull ' 187 



862. brain 188 



863. male urinogenital organs . . . .189 



864. embryo in egg-shell .... 191 



865. Salmofario 192 



866. head . 193 



867. scale 194 



868. vertebrae 195 



869. caudal end of vertebral column 196 



870. skull 197 



871. fario, skull disarticulated 199 



872 ,, salar, of young individual 202 



873. fario, fin-ray 202 



874. shoulder-girdle and pectoral fin 203 



875. pelvic fin 204 



876. ,, side dissection 205 



877. brain 207 



878. eye . '. 208 



879. auditory organ 209 



880. urinary organs 209 



881. development 210 



882. section of blastoderm 210 



883. Polypterus bichir 212 



884. Acipenser ruthenus 212 



885. Lepidosteus platystomus 213 



886. Amia calva 213 



887. Rita buchanani 214 



888. Gadus morrhua 214 



889. Sebastes percoides 215 



890. Labrichthys psittacula 215 



