Pi. ATi; XXI. 



Fig. 75 Halecium parvulum. 



A. Natural size. 



B. Portion of stem showing mode of branching and male gonophorei 



C. Female gonophores. 



Fig. 7(>. Halecium pygmœum. 



A. Natural size. 



B. Colony showing branching. 



C. Female gonophore. 



D. Male gonophores. 



Fig. 77. Halecium revers um. 



A. Natural size. 



B. Portion of branch showing position of nodes. 



C. Branch rising from fascicled stem. 



Fig. 78. Halecium scutum. 



A. Natural size. 



B. Portion of branch showing length of internodes. 



C. Gonangium. 



Fig. 79. Halecium tenellum. 



A. Natural size. 



B. Colony showing branching. 



C. Gonophores (After Nutting). 



