GENERAL INDEX 535 
Skeleton, aponeurotic, 414 
3 Cephalaspis, 414, 445 
53 evidence of the, 119 
5 Limulus, cartilaginous, 126, 136 
is 5 mesosomatic, 137 
Pe 9 prosomatic, 142 
re Petromyzon, 125 
a Vertebrate, commencement of bony, 120, 121 
Skin, digestive power of cells of, in Ammoccetes, 58, 442 
», of Ammoccetes, 346 
» nerves of, 448 
Skull of dogfish, 123 
»  pig-embryo, 121 
Slimonia, 27, 56, 170, 235, 238, 249, 276, 308 
Solenocytes, 395, 477 
Solpugide, 109 
Spheroma serratum, brain, 62, 90, 101, 225 
Spiders, eyes, 75 
» stomach, 109 
Spina bifida, 50 
Spinal cord, difference between brain and, 45 
5 » region of, 385 
5 » termination in bird-embryo, 51 
Spondylus, retina of, 114 
Squilla, eyes, 100 
» glands, 422 
Stomach, cephalic, 4, 43, 102, 244 
Stylonurus Lagani, 27, 235, 289, 249 
Substantia gelatinosa Rolandi, 44 
Suprarenal body, 423 
Surfaces, dorsal and ventral, 11 
5 reversal of, 15, 29, 36, 87, 175, 352, 433, 484 
Synapse, 72 
Syricytium, 464, 471, 479 
Tatu of lizards, 50 
Tapetum, 69 
Teleosteans, 23, 345, 420, 424 
Tendon-organs, 470 
Tentacles of Ammoccetes, 246, 289, 303 
Tergo-coxal muscles, 247 
Test, biological, of relationship of animals, 492 
Thalamencephalon, 48 
Thelodus, 344 
Thelyphonus, 231 
5 brain, 58, 54, 56, 224 
i » caudal, 450 
4 cecal diverticula, 109 
entosternite, 143 
genital organs, 206 
lyriform organs, 368 
-, olfactory passage, 226, 306 
