HUDSANSEORGANENE HOS SPINAX NIGER, BONAPARTE 349 



Text fig. 8 (pag. 321). The same of the lateral canal midway between two 



nerves. 



Note: No lateral epithelial folds with blodvessels, no epithelial 

 ridges at each side of the sense ridge, which is very low and 

 runs along one of the lateral walls (X 50). 

 Text fig. 9 (pag. 329). Transverse section through the middle of a hyo- 



mandibular pit organ (X 50). 

 Text fig. 10 (pag. 331). The same (X 200). 

 Text fig. 11 (pag. 340). Transverse section through ampullae (X 50). 



In epidermis serveral lightorgans are to be seen. 



Index letters (fig. 3-11). 



h 



= 



goblet cells- 



ha 



=1 



basal membrane. 



hi 



= 



connective tissue in the sense ridge. 



hs 



= 



connective tissue sheath. 



c 



= 



cupula. 



CC 



= 



cylindrical cells of the epithelial ridges. 



cl 



= 



epithelial ridges. 



centr 



p = 



central plate. 



cut 



= 



cuticula. 



div 



= 



diverticles. 



ep 



= 



epidermis. 



ep.f 



= 



epithelial fold of the pit organs. 



f 



= 



connective tissue fibres. 



k 



= 



bloodvessel. 



M 



= 



epithelial folds with bloodvessels in the sensory canals, 



1 



= 



corium. 



ly 



= 



lightorgan. 



n 



= 



nerve. 



P 



= 



pigment. 



Pf 



= 



fold of the pigment layer. 



pl 



= 



placoid scales. 



s 



= 



tubule. 



sa 



= 



sensory bud. 



sac 



= 



sensory cells. 



sap 



= 



sensory papillæ. 



sh 



= 



subcutanous connective tissue. 



se 



= 



secretion. 



sept 



= 



fibrous septæ between the diverticles of the ampullæ. 



ste 



= 



supporting cells. 



stk 



= 



their nuclei. 



t 



= 



the thin exterior epithelial wall of the sensory canal. 



