LATEKAL CANAL SYSTEM OF SELACHIANS 33 



Lot. Cn. 



m:\ #. 



^5- :v* CV,V %,^-'^ ' 



/^.®/^y .'^ 



Fig. 23 Caudal end of a bo nun. Alustelus embryo. Note that the pores of 

 the tubules become larger and somewhat elongated posteriorly to the point where 

 the canal merges into an open groove. X 4J. 



Fig. 24 Transverse section, lateral canal of a 65 mm. eml)ryo, posterior to 

 first dorsal fin. Note the small lumen. Mustelus X o92. 



Fig. 25 From the same specimen as figure 24, liut farther cephalad, where 

 the lumen of the canal is much larger. 



THE JOURNAL OF COMPARATIVE NEUROI-OGY, VOL. 28, NO. 1 



