348 GUDRUN RUUD 



Explanation of Text figures. 



Text fig. 1 (pag. 298). Dorsal view of the head of a 110 mm. embryo of 

 Spinas niger showing the course of the sensory canals, drawn after 

 their surface pores, the pit organs and the pores of the ampuUery 

 canals. (X 5). 



Text fig. 2 (pag. 299). Ventral view of the same. (X 5). 



(On the buccal group of ampullæ only the outline is drawn). 



Text fig. 3 (pag. 301). Side view of the same (X 5). 







index letters (fig. 1 — 3). 



ha 



= 



pores of the buccal group of ampullæ. 



hm 



= 



hyomandibular canal. 



hma 



= 



pores of the hyomand. group of ampullæ. 



Jimp 



— 



hyomand. pit line. 



I 



= 



lateral canal. 



io 



= 



infra-orbital canal. 



so 



= 



supra-oi'bital canal. 



soa 



z= 



pores of the superficial ophthalmic group of ampulla 



st.p 



= 



supratemporal pit organs. 



v.p 



= 



ventral pit line of the body. 



B 



= 



pectoral fin. 



End 



= 



auditory pore. 



a 



= 



gill clefts. 



M 



= 



mouth. 



N 



= 



nasal aperture. 



Sp 



= 



spiraele. 







= 



Eye. 



Text fig. 4 (pag, 306. Pit organ from the dorsal pit line of the body, cleared 



up and mounted in canadabalsam, showing the pigmentation and 



arrangement of lightorgans around (X 40). 



sp = fissure, which leads into the pit with the sensory papilla. 



I = lightorgan. 



p = pigment cells of the skin. 



Text fig. 5 (pag. 318)= Transverse section of the infraorbital canal (from 



its præoral part) between two tubules (X 31). 

 Teyt fig. 6 (pag. 319). The same with nerve and tubule (X 31). 

 Text fig. 7 (pag. 320). Transverse section of sensory bud (X 300). 



