xii LIST OF ILLUSTRATIONS 



FIG. PAGE 



833. Centrophorus calceus, dermal denticles 172 



834. Scymnus, spinal column . 172 



835. Urolophus testaceus, skeleton 174 



836. Heptanchus, skull 175 



837. Torpedo-Ray, showing electric organ 177 



838. Cestracion galeatus, egg-case 181 



839. Pristiurus, section of blastoderm 182 



840. ,, formation of mesoderm 183 



841. Elasmobranch embryo, sections 184 



842. Scyllium canicula, embryo 185 



843. Ray, embryo 185 



844. Elasmobranch embryo with yolk-sac 186 



845. Scyllium canicula, head of embryo 187 



846. later stage 187 



847. Chimsera and Callorhynchus . 189 



848. ,, vertebral column 191 



849. skull 192 



850. Callorhynchus antarcticus, skull 193 



851. brain 194 



852. ,, ,, male urinogenital organs . . . 195 



853. ,, ,, embryo in egg-shell .... 197 



854. Salmo fario 198 



855. head 199 



856. ,, scale 200 



857. ,, vertebrae 201 



858. ,, caudal end of vertebral column 202 



859. ,, skull 203 



860. ,, fario, skull disarticulated 205 



861. ,, salar, ,, of young individual . 208 



862. ,, fario, fin-ray 208 



863. ,, ,, shoulder-girdle and pectoral fin 209 



864. ,, ,, pelvic fin 210 



865. ,, ,, side dissection 211 



866. ,, brain 213 



867. ,, ,, eye 214 



868. ,, ,, auditory organ 215 



869. ,, ,, urinary organs 215 



870. ,, ,, development 216 



871. ,, ,, section of blastoderm 217 



872. Polypterus bichir .218 



873. Acipenser ruthenus . 219 



874. Lepidosteus platystomus 219 



875. Amiacalva 219 



876. Rita buchanani 220 



877. Gadus morrhua . 22 1 



878. Sebastes percoides 



879. Labrichthys psittacula 222 



880. Ostracion . . 223 



