EXPLANATION OF PLATE XIX. 



Fig. 19. Cross-section of Eigenmannia virescens (Valenciennes). 



Fig. 20. Cross-section of Sternarchus albifrons (Linnaeus). 



Fig. 21. Cross-section of Ekcirophorus electricvs (Linnaeus). 



Fig. 22. Cross-section of Electrophorus eleciricus (Linnaeus). 



Fig. 22. Cross-section of Eledrophorus eleciricus (Linnaeus). 



Fig. 23. Cross-section of Eledrophorus eleciricus (Linnaeus) near end. 



Fig. 24. Pseudo-electric tissue of Eigenmannia virescens (Valenciennes) after Sachs, a. end of tail; b. cross- 

 section through same; li. point corresponding to that occupied by the electric organ of Electrophorus 

 eleciricus (Linnaeus); gy. axis of distribution of structural units, wliich are indicated by c; d. nerve- 

 fibers; (after Sachs " Untersuchungen am Zitteraal" p. 69). 



Notation of Figs. 19-23. 



6. S., bundles of Sachs: d., dorsalis; d. t., dorsal thong; H. o., Hunter's organ; I. in., lateralis inferior; 

 I. im., lateraUs imus; I. o., large electric organ; I. s., lateralis superior; n. c., notalis externalis; n. i., notalis 

 internalis; p. e. a., pinnaUs anaUs externalis; p. a. i., pinnaUs analis internalis; p. e. o., pseudo-electric organ; 

 r. I. i., remnant of lateralis imus; S. o., organ of Sachs; v., ventralis. 



204 



