young, [473]

Hartmeyer, [38]

Hasselt, van, [36]

Hatching, of eggs, [417]

Hatschek, [113];

grove of, [128]

Haus, of Appendicularians, [66]

Head, shape and relative size, [153]

Heart, of Tunicata, [49], [67];

of Fishes, [327], [328]