Plate 4. 



Fig. 14-17. Bassozetus nasus Garman. 



Fig. 14. The fish seen from the side. Di-awing ; natural size. 



Fig. 15. A radiating disc in transmitted light. Photograph ; magnified 1 : 58. n, main disc 

 nerve ; p, reticulation formed by the pigment cells with their long processes. 



Fig. 16. A radiating disc in transmitted light. Photograph; magnified 1 : 27. n, main disc 

 nerve ; p, reticulation formed by the pigment cells with their long processes. 



Fig. 17. Transverse section of a radiating disc. Stained: haematoxylin. Drawing; mag- 

 nified 1 : 42. b, blood vessels ; c, paratangentially arranged connective-tissue 

 cells ; u, main disc nerve ; p, basal pigment cells. 



