136 MR, E. PHELPS ALLIS, JUN., ON 



the ligament breaks up into numerous branches which spread in 

 every direction along the internal surface of the fibrous mem- 

 brane. From the anterior surface of the columnar portion of 

 tlie ligament a branch ligament is sent anteroventrally beneath 

 the fibrous membrane. The little cartilaginous eminence s, shown 

 in Schauinsland's figures of Callorkynchus on the dorsal surface 

 of each n;isal capsule, corresponds approximately, in position, to 

 this ligament of Chimcera. 



4. Ampallce. 



The ampulhe were examined in two specimens. In one of 

 these specimens there were five large occipital ampullary pores 

 Iving in line along the anterior edge of that portion of the 

 supratemporal commissure (lateral canal, Cole, 1896) of the 

 latero-sensory canals that lies between the posterior ends of the 

 supraorbital and infraorbital canals. The tubules that start 

 from these pores immediately penetrate a subepidermal mem- 

 brane which extends over nearly the entire surface of the head, 

 and, lying in that membrane, between external and internal 

 layers of it, run forward dorsal to the orbit and terminate in a 

 group of five ampullfe that lie immediately dorso-lateral to the 

 mediiin rostral process, these ampullar also lying between the two 

 layers of the subepidermal membrane. Dorso- anterior to the' 

 eyeball, between it and the supraorbital latero-sensory canal, 

 there is a group of twelve supraorbital pores, the tubules from 

 which also penetrate the subepidermal membrane and, running 

 antero-ventially, terminate in an equal number of ampulla3 that 

 lie ventral to the ampullte of the occipital pores and, like them, 

 between the two layers of the subepidermal membrane. Anterior 

 to these supraorbital pores, in the anterior end of the space 

 enclosed between the supraorbital and suborbital latero-sensory 

 canals, there are three groups of pores more or less contiguous 

 one with the other. In the two dorsal groups together there 

 were thirty pores, and in the ventral group twelve pores. The 

 tubules from the two dorsal gi'oups penetrate the subepidermal 

 membrane, and running dorsally, dorso-posteriorly or posteriorly, 

 terminate in ampullae that lie between the two layers of the 

 subepidermal membrane, close to the ampidlfe of the supra- 

 orbital pores. The tubules of the ventral group perforate first 

 the outer and then the inner layer of the subepidermal mem- 

 brane and terminate in ampullae that lie close against the 

 internal surface of that, membrane, in the region between the 

 dorsal and lateral rostral processes. Ventral to this latter 

 o-roup of pores there are numerous pores, many of them minute, 

 covering that portion of the ventro-lateral surface of the snout 

 that lies between the suborbital latero-sensory canal and the 

 supramaxilhuy fold, and antero- mesial to the point where the 

 supraorbital canal joins the outer buccalis canal. The tubules 

 leading from these pores all run dorsally between the two layers 



