112 EDWARD PHELPS ALLIS, .TUN. 



plane of the external openings of the endolymphatic ducts. 

 These last six pores formed, in all my specimens, one of the 

 most distinctly evident lines of pores on the entire head of 

 the fish, and this line would seem to occupy the position 

 ascribed by Garman (21) to the supratemporal commissure of 

 Chlamydoselachus — a position, however, also held by two sur- 

 face sense organs to be later described. There were twenty- 

 six pores in this sub-group on one side of the head of the 

 specimen used for the drawings, and twenty- nine on the other. 



All of the ampulla) of the entire group of superficial 

 ophthalmic ampullae are innervated by branches of the ramus 

 ophthalmicus superficialis, in a manner that will be related 

 in describing that nerve. 



The deep ophthalmic group of ampnllie lies about half way 

 between the nasal aperture and the anterior end of the head, 

 there lying in the region included between the prenasal 

 section of the infra-orbital lateral canal, and the rostral and 

 subrostral sections of the supra-orbital canal. In transverse 

 sections that pass through the posterior portion of this group 

 of ampullas, they are seen to form a curved line, extending 

 from the internal surface of the prenasal section of the 

 infra-orbital canal dorsally, and laterally toward the rostral 

 section of the supra-orbital canal. This curved line lies 

 slightly ventro-lateral to a line connecting the ventro-mesial 

 and dorso-lateral rostral bars of cartilage, the most lateral 

 ampullae lying lateral to the dorso-lateral bar. Anteriorly 

 the ampullae form, in sections, an irregular group that lies in 

 nearly these same relations to the lateral canals and rostral 

 bars. Posteriorly the anterior end of the nasal capsule 

 presses into the group, and separates it, in sections, into two 

 parts, one part lying ventro-mesial to the nasal capsule, and 

 the other lying on its dorsal surface. Most of the tubules of 

 the group radiate downward from the ampullae, running in 

 every direction toward the ventral surface of the snout ; but 

 some of them first extend downward and laterally, then turn 

 upward and backward as they approach the lateral edge of the 

 snoutj and thus reach its dorso-lateral surface. These latter 



