PLATE XV. 
Fig. 87.—Cellaria mandibulata Hincks. Two zoecia, young stage show- 
ing lateral crenulated border (er. bd.). 
Fig. 88.—C. mandibulata. Several zowcia at an older stage, showing 
operculum (op.) with its four denticles (d.), the immersed owcia above, 
their orifices (oe. or.) only visible, and an avicularium with its large man- 
dible (man.). The crenulated border (cr. bor.) has formed above and he- 
low the zoccia, thus surrounding them. X 50. 
Fig. 89.—C. mandibulata. Three zowcia at a still older stage to show 
inerease of caleareous wall and final form of omecial orifice (0e. or.) re- 
sembling a small avicularium. X 50. 
Fig. 90.—Cellaria diffusa sp. nov. A few zowcia (¢@.) to show shape, 
oecial orifice (oe. or.) with the lower margin developed into a mucro (m.), 
and the avicularia (av.). X 50. 
Fig. 91—Flustra lichenoides Robertson. A few zocwcia enlarged to show 
erect spines (é. sp.), operculum (op.), and omcia (0e.). X 50. 
Fig. 92.—F. lichenoides. The dorsal surface of a few zowcia showing 
rcot fibres springing from the distal angle of each zowcium. 
lig. 93.—Flustra membranaceo-truncata Smitt. Habit sketch. 
Fig. 94.—F. membranaceo-truncata. A few zoecia showing arrange- 
ment, immersed oewcia (0e.), and avicularium of simple structure in place of 
zoecium (av.). X 50. 
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