52 



PART I. GENERAL ACCOUNT 



com 



Ые 



Fig. 37. Epidermis of Spirobrachia grandis in the brain region, in transverse section. 

 сер - epidermal cell; en 1 - multipolar nerve cell; en 2 - unipolar nerve cell; com -transverse commis- 

 sure; con - longitudinal bundle of nerve fibres; «-sensory cell; cut - cuticle; lac- lacuna; 

 mb - basement membrane; se - secretory droplet of cuticular substance; ton - tonofibrillae. 

 (After Ivanov, 1958b.) 



