Homol"gy of pituitary body of Ammocœtes and coxal glands of Limulus, [319]

Homol"gy of tubular muscles of Ammocœtes and veno-pericardial muscles of Limulus, [309]

Homol"gy of ventral aorta of vertebrate and longitudinal venous sinuses of Limulus, [178]

Hydra, [441], [465], [472], [476]

Hydrophilus larva, eye, [84]

Hyoid segment in Ammocœtes, [186], [267]

Hypoblast, [434], [438], [444], [445], [459]

Hypoctonus, cartilage cells in entosternite, [133]

Hypo"tonus, operculum, [189], [207]

Hypogastric plexus, [3]