﻿IX, D, 3 



Light: Some Philippine Scyphomedusx 



229 



canals divide the radial muscle into triangular areas which are 

 widely separated proximally. 



The genital ostia are as wide as the interostial pillars, and 

 are partly closed by 1 large median papilla and 2 smaller, lateral, 

 elongated, roughened, wartlike papillae, each lying in the line 

 of a radial canal. The partitions between the 4 genital cavities 

 are narrow but complete. 



The arm disk is supported by 4 broad, flat pillars. The 

 distance from the base of one of these to the base of the one 

 opposite it is 170 mm. The united arms arise from the center of 

 the arm disk, and are only 60 mm. in diameter where they leave 



Fig. 16. Rhopilema visaywna, a diagram of the arrangement of the ducts of two mouth arms 

 supported by a common pillar and of their scapulets. X i. 



the disk. The mouth arms, measured from the outer surface of 

 the arm disk, are 190 mm. in length. They are united proximally 

 for more than two-thirds of this distance, the distal free portion 

 measuring 75 mm. When the arms are spread out, the specimen 

 is 200 mm. from the tip of one arm to the tip of the arm 180° 

 from it, the central united portion being 50 mm. across at this 

 point. The 3-winged portion of the arm makes up less than 

 one-half of the free distal portion of the arm. Each of the two 

 outer wings bears a dichotomously divided branch near its origin, 

 and is divided distally into 4 flattened, tapering, nearly naked 

 branches. Scattered among the mouths are appendages of three 

 types: Long, flexible, somewhat flattened, filamentous append- 



