Trilo"ites, appendages, [351], [437]
Trilo"ites, diagram of section through a trilobite-like animal, [413]
Trilo"ites, dominance of, [26]
Trilo"ites, excretory organs, [396]
Trilo"ites, glabellum, [339]
Trilo"ites, relations of, [249], [283]
Trilo"ites, respiratory apparatus, [170]
Trilo"ites, ventral surface, [437]
Tube of central nervous system, [37], [38], [42], [102], [211], [433], [455], [457]