832 



INDEX 



Sarsia, 139, 182, 

 ocellus of, 139 

 Saturnia pernyi, development of eye, 156 

 Sauropsida. See Reptiles and Birds. 

 Saw-fly, 220, 223 



larvae, ocelli of, 141, 223 

 See also Neodiprion. 

 Saxicola, 417 



infula in, 417 

 Scallop. See Pecten. 



Scalops aquaticus, degenerate eyes in, 733 

 Scaphiopus, pupils, 339 

 Scaphirhynchus, 315 



pupils, 317 

 Scaphopods, 196 



neuro -secretory cells, 552 

 sense organs, 197 

 Sceloporus, retinal pigment in, 361 

 Schistocerca gregaria, dorsal light reaction 

 in, 74 

 ommochromes in, 123 

 Schistosoma, 187 

 Schizopods, eyes of, 160, 591 



See also Stylocheiron, Mysids. 

 Schlemm, canal of, 473 

 Sciuridse, 445 



accommodation in, 653 

 area centralis, 485 

 choroid, 457 

 ciliary region, 460 

 colour vision in, 633 

 diurnality of, 604 

 lens, 474 



ocular movements of, 696 

 optic axis, 688 



disc, 686 

 refraction of, 639 

 retina, 485 



pure -cone, 612 

 vascularization of, 479 

 vision of, 601 

 visual acuity of, 663 

 cells, 483 



field, binocular, 689 

 Sciuromorpha, 445 



Sciurus vulgaris. See Squirrel, common. 

 Sclera, characteristics in 

 amphibians, 334 

 birds, 403 

 chelonians, 369 

 chimseras, 290 

 chondrosteans, 317 

 dipnoans, 313 



Sclera, characteristics in 

 holosteans, 321 

 lacertilians, 356 

 lamprey, 265 

 Lati?neria, 315 

 marsupials, 438 

 monotremes, 433 

 placentals, 450 

 selachians, 281 

 snakes, 385 

 Sphenodon, 380 

 teleosts, 292 

 Scleral cartilage. See Cartilage. 



ossicles. See Ossicles. 

 Scolopendra ■rnorsitans, 210 

 Scombridse, adipose lids in, 311 



See also Thunnus. 

 Scopelarchus analis, tubular eyes of, 323 

 Scorpcena, 302 

 fundus, 306 

 tensor choroidese, 302 

 twin cones, 308 

 Scorpion, 211 



ocellus, lateral, 140, 141, 211 



median, 150, 212 

 pseudo-. See Pseudoscorpions. 

 whip-. See Whip-scorpions. 

 Scotocytes, 251 

 Scototaxis, 31, 60 

 Scutigera, 160 



eyes of, 160, 210 

 Scylliorhinus, 287 



ciliary papilla, 284 

 optic pedicle, 290 

 pvipils, 286, 287 

 canicula, 280 

 Scyllium. accommodation in, 647 

 blinded, behaviour of, 598 

 colour changes in, 95 

 Scymnus, brain, 533 

 Scyphozoa, 182 



See also Jellyfish. 

 Sea-anemones, 182 

 nerve fibrils in, 514 

 nervous responses, 515, 516 

 phototactie reactions of, 571 

 See also Actinia. 

 Sea-cows. See Sirenians. 

 Sea-cucumbers, 184 

 sensitivity of, 184 

 See also Holothuria. 

 Seagulls. See Laridae. 

 Seal, 445 



