PLATE V. 



Group of six spicules, o, b, c, </, £ -, ƒ, of /sis hippuris Linn. 120. 



Group of five spicules, a, b, c, d, e of /sis reticulata Nutting 120. 



Group of thrce spicules, a, b, c, of Ceratoisis wrighti Nutting 64. (Approximately one half of 



each spicule is show n . 



Group of three spicules, a, b, c, of Acanella siboga Nutting 120. 



Group of four spicules, a, b, c, J, of Mopsea flava Nutting 120. 



Group of three spicules, a, b, c, of Acanella weberi Nutting 120. 



