242 DISCOVERY REPORTS 



paired shell nerves. There are anterior and posterior pericardial nerves mentioned above 

 in this summary. 



A well developed visceral system, based on the same plan as that of Dolorio, is 

 present and in addition there are very large visceral ganglia associated with the aorta 

 (Figs. 10, 12). 



The giant fibre system so conspicuous in Doloria does not appear to be present in 

 Gigantocypris. It is suggested that this and other evidence indicates that a giant fibre 

 system appears to be a nervous mechanism which has evolved to co-ordinate escape 

 movements. 



The walls of the end sac of the antennal gland are extremely thick and labyrinthine. 

 In the intracellular cavities blood cells can be seen moored to the walls of peculiar 

 amoeboid processes (Plate XLI, fig. 6). 



The sphincter between end sac and duct consists of four cells containing an intrinsic 

 system of fibres arranged in a tetrahedral plan. They are not connected to the ectoderm 

 (Fig. 17). 



