Tuni"ata, endostyle, [198], [212]
Tuni"ata, hypophysis, [425]
Tuni"ata, notochord, [438]
Tuni"ata, position of, [494]
Unit, appendage, in non-branchial segments, [185]
Ui"t, branchial, [161], [165], [168], [185]
Ureters, nerves of, [448]
Uterus of Scorpion group, [189], [202], [203], [204], [205], [214]
Utr"us vertebrate, nerves of, [448]
Valve, ileo-colic, [449]