518 THE ORIGIN OF VERTEBRATES 
Ammocetes, epithelial cells of skin, 347 
35 » pits, 173, 200 
& eye, 98 
Pf », muscles, 267 
is », median or pineal, 63, 75, 76, 77, 78, 80, 85, 86 
” ” ” left, 78, 719 
“ fat-column, 181, 182 
“ ,», in degenerated muco-cartilage, 338, 334 
i ganglia in embryo, 229, 288 
v5 gland-tissue round the brain, 209, 210, 879 
% head-region, 128, 162, 163, 193, 293, 294, 296, 298, 335 
4 head-shield, 329, 831, 338 
+ liver, 442, 452 
es lymphatic glandular tissue, 426 
ms Miillerian fibres, 489 
is ‘muscles, eye, 178, 267 
i Pr lip, lower, 297 
a 4 » upper, 305 
9 ay respiratory, 171 
es ay somatic, 332, 336, 409 
e ‘ tubular, 173, 298, 309 
PF nerves, cranial, 144 
_ » facial, 186, 311 
fe $4 glossopharyngeal, 186 
i ra optic, 105 
e es trigeminal, 232, 288, 288 
si vagus, 153, 173, 186 
nerve-fibres, medullation of, 20 
ts notochord, 182, 485 
i olfactory tube, 219, 225, 227, 317 
“ oral chamber, 317, 248, 287, 458 
as parasitism, 60, 286 
a pituitary, 321 
e prosomatic region, 243 
5 pronephric duct, 402, 405 
i relationship to Ostracodermata, 326, 338, 344, 414, 416 
33 retina, 93, 144 
- skin, 58, 346, 348, 442 
5 skeleton, 125, 126, 132, 291, 296, 335 
6 segments, comparison with segments of Eurypterus, 323 
c- a facial, 201 
ss 57 hyoid, 186, 201 
7 - prosomatic, 286 
"4 septa between myomeres, 416 
5 tentacles of upper lip, 303 
3 test, biological, to show relationship with Limulus, 493 
a thyroid, 192, 194, 196, 205, 213, 430 
a transformation, 18, 59, 125, 168, 193, 199, 200, 220, 227, 228, 287, 291, 
304, 307, 309, 331, 336, 347, 349, 389, 445 
‘i velum, 228, 289, 298, 302 
Ameebocytes, 473 
Amphibia, 23, 345 
