224 Journal of Comparative Neurology. 



four in all. Each sensory club hangs in a niche of the exum- 

 brella and is attached by a small peduncle, whose central canal 

 is connected with one of the four stomach pockets and in the 

 club proper forms an ampulla-like enlargement. 



Each club is said to lie in a perradius, and belongs to the 

 subumbrella, as is shown by the course of the vascular lamellae, 



Explanation to Fig, /. This is an outline taken from Sclievviakofif's Fig. 7 

 and is placed here to show the general relations of the different parts of a 

 club. Since this drawing represents a section the simple eyes are not indicated. 

 C — concretion cavity ; CO — cornea; CP — capsule; CSC — cavity of sensory club, 

 EC — ectoderm; EN — endoderm; ENC — endoderm of sensory club ; L — lens; 

 NC — network cells; NF — nerve fibers; KT — retina; SLA — supporting la- 

 mella; VB — vitreous body. 



bands of cells, which passing through the jelly from endoderm 

 to ectoderm all around the margin, form the line of division be- 

 tween sub- and exumbrella. 



Each club has six eyes. Two of these on the mid-line of 



