12 AKT. 7. K. KISHINOUYE. 



covered with numerous brown dots, of which those on the per- 

 radial sides differ in form and arrangement from those on the 

 interradial sides. 



The subgenital cavity is flat ; though not divided into four 

 separate cavities, it is four-lobed, being separated by four per- 

 radial septa, The length of each of these septa is about one 

 fourth that of the broadest part of the cavity (fig. 9). In con- 

 tinuation of these septa there are narrow gelatinous thickenings 

 in the gastrogenital membrane or the roof of the subgenital cavity. 

 Naturally these gelatinous thickenings form a cross. This cross 

 is a little curved and is not much separated from the upper 

 surface of the oral disc, while the remaining portion of the 

 gastrogenital membrane is very thin and loose. 



The canal system in general resembles that of Netrosoma 

 typhodendrium L. Schultze. Of the interocular radial canals 

 there are twenty-four. The eight ocular canals are larger than 

 other radial canals and run straight to the umbrella margin (tig. 

 10). So do likewise the eight adradial canals, but these are not so 

 distinct, The sixteen remaining canals are branched just outside 

 the oral disc and together with other canals form a complicated 

 network. The meshes are mostly polygonal near the central 

 portion of the subumbrella, but become rectangular near the 

 periphery. Near the margin of each marginal lobe, the network 

 ends with only one mesh, which sends a very short, blind canal 

 towards the umbrella margin. For about one-third its length at 

 the axial portion, the ocular canal is free from side branches. 

 There is no circular canal. The eight brachial canals originate 

 from depressions on each side of the perradial septa of the sub- 

 genital cavity. These adradial depressions in the central stomach 

 cavity correspond to the pillar canals of other monodeniniate 



