﻿208 The Philippine Journal of Science i9u 



Sixteen radial canals, 8 of which are rhopalar and 8 adradial, 

 leave the cruciform central stomach. The ocular canals extend 

 past the ring canal to the sense organs, while the adradial 

 canals end in the ring canal. The fine-meshed network of canals 

 outside the ring canal extends to the margin. The coarser 

 inner network is always connected with the adradial canals, 

 seldom with the ocular canals, and never with the stomach. 



The sense organs have in life brilliant silver spots which 

 fade in preserved specimens. The size of these ocelli is in 

 inverse ratio to the size of the medusa. 



The medusa is deep purplish brown in life, and fades to dull 

 brown in formalin. 



This is the commonest medusa of Manila Bay. During the 

 months of November and December it is especially abundant on 

 the beach at Pasay just outside of Manila. The fishermen say 

 that these jellyfish are blown in by southwest winds which pre- 

 vail during these months. The largest specimen in the collection 

 measures 105 mm. in bell diameter, but I have seen many con- 

 siderably larger specimens. Mayer reports this species as living 

 on the bottom in shallow water. I hardly think this is the case, 

 as they are always to be seen on or near the surface in shallow 

 water along the beach and in the esteros (brackish water canals) , 

 where they sometimes occur in countless numbers. The im- 

 mature medusas vary considerably. Some are transparent white, 

 and resemble in general appearance the immature forms of 

 Acromitus maculosus gen. et sp. nov. which is described later 

 in this paper. The chief and most apparent difference is, of 

 course, the absence of appendages of any kind on the mouth 

 arms of Catostylus. Others resemble in general form the mature 

 medusas, but have such striking differences that I have thought 

 it worth while to give a short description of one of them. 



Catostylus purpuras Mayer, immature form. 



The bell, which measures 27 mm. in diameter, is more con- 

 vex than a hemisphere when relaxed and much more so in con- 

 traction. The margin in life hangs down below the short mouth 

 arms, but in formalin is curved inward exposing the mouth arms. 

 There are 8 prominent rhopalia, which in life have a bright 

 silvery color. The exumbrellar sensory pit is broad and shallow 

 and dendritically grooved. The ocular lappets are roundly 

 pointed and longer than the velar lappets. There are typically 

 10, sharply pointed, narrow, velar lappets between each 2 ocular 

 lappets arranged as in the adult medusa. 



The subgenital ostia are irregular in size and from once 



