Explanation of Plates. 





Index 



Letters. 



ana 



Anterior nasal aperture. 



Ilo 



eo^-^ 



Ethmoidal lateral sensory 



NA 





organs. 



Ol 



ep^ 



Ethmoidal pore'. 



pmo 



c'-s^p 



Compound pore, ethmoidal" 







— subraorbitaP. 



pmp^~^^ 



e'^s'^p 



Compound pore, ethmoidal'^ 







— supraorbital^ 



pna 



hsc 



Horizontal semicircular canal 



POP 





of ear. 



so^—^ 



ic 



Infraorbital lateral canal. 





io^-'^ 



Infraorbital lateral sensory 



sp^-^ 





organs. 



SQ 



ip^-^ 



Infraorbital pores or pouches. 



sio^-^ 



pm i^p 



Compound pouch, infraorbi- 







tal ^^ — preoperculo- mandi- 



stp^ 2 





bular 12. 





i^s^p 



Compound pouch, infraorbi- 



tr 





tal® — supraorbital". 



V 



Lateral line sensory organ. 

 Nasal bone. 

 Olfactory nerve. 

 Preoperculo-mandibular late- 

 ral sensory organs. 

 Preoperculo - mandibular 

 pores or pouches. 

 Posterior nasal opening. 

 Preoperculum. 

 Supraorbital lateral sensory 

 organs. 



Supraorbitalpores orpouches 

 Squamosal. 



Supratemporal lateral sensory 

 organs. 



Supratemporal pores or 

 pouches. 

 Trochlearis. 

 Blood vessel. 



Description of Plates. 



Fig. 1. 



g- 2 



g- 3 

 g- 4 



Side view of the head of Ophicthys serpens, showing the pores of the 



lateral sensory canals, and the more evident surface sense organs. 



Natural size. 



Top view of the same. Natural size. 



Bottom view of the same. Natural size. 



Diagrammatic lateral view of the lateral sensory canals on the head of 



the same, a few of the enclosed sense organs, that were distinctly evident 



in dissections, alone being shown. Natural size. 



