PLATE V. 

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Fig. i. Group of six spicules, a, b, c, d, e, f, of I sis hippuris Linn. X 120. 



Fig. 2. Group of five spicules, a, b, c, d, e of I sis reticulata Nutting X 120. 



Fig. 3. Group of three spicules, a, b, c, of Ceratoisis wrighti Nutting >< 64. (Approximately one half of 



each spicule is shown). 



Fig. 4. Group of three spicules, a, b, c, of Acanella sibogce Nutting X I2O. 



Fig. 5. Group of four spicules, a, b, c, d, of Mopsea flava Nutting X 120. 



Fig. 6. Group of three spicules, a, b, c, of Acanella weberi Nutting X 1 20. 



