CILIATED PITS OF STENOSTOMA 243 
Fig. 4. Ciliated pit with its ‘homogeneous mass’ (hm); fundus epithelium 
(fe); marginal epithelium with its cilia (mge), and pit-ganglion (g) well es- 
tablished; the latter receiving a bundle of fibres from ‘brain’ (br). (mus) Mus- 
cles. X 1500. 
base. Over the base is spread the ‘homogeneous mass’ elabo- 
rated by the epidermis of the fundus into which the sensory 
rods of the ciliated pit-ganglion cells extend and test the chem- 
ical nature of the water, conveying the sensations obtained to 
the pit-ganglion, which merges into the ‘brain.’ 
In these results we have been able to confirm the descrip- 
tion of Ott (92) so far as the general structure of the pits is 
concerned, but have not, however, been able to agree with his 
description of the fundus of the pit. He says ‘‘the cilia of the 
