THE SKULL OF CHIMJERA. 



137 



of the subepidermal membrane, and apparently all perforate the 

 inner layer of that membrane and terminate in ampullae that lie 

 internal to it, in the region between the dorsal and lateral rostral 

 processes. The tissues were, however, here so dense and tough 

 that the relations of all of these ampulla? to the membrane could 

 not be definitely determined. 



The ampulla? above described are all innervated by branches of 

 the ramus ophthalmicus superlicialis trigemini, these branches 

 being all given off after that nerve issues from the ethmoidal 

 canal through its anterior opening, the branches destined to the 

 ampulla? that lie between the two layers of the subepidermal 

 membrane all perforating the inner layer of that membrane to 

 reach the ampulla?. These ampulla? correspond, in position, to 

 the larger one of the two supraorbital groups of Cole's (1896) 

 descriptions of Chimcera monstrosa, the smaller group of supra- 

 orbital pores of that author's descriptions having approximately 

 the position, in Chimcera colliei, of a group of ampulla? that are 

 innervated by the nervus buccalis. 



Cole says (1896, p. 655) that the ramus oticus facialis supplies 

 "the most ventral of the ampulla? opening on the surface by the 

 large occipital pores." No such branches of the ramus oticus 

 could be found in my specimens of Chimcera colliei, and as the 

 ampulla? related to these occipital pores all lie on the dorsal surface 

 of the snout, at a great distance not only from the related pores 

 but also from the branches of the oticus shown in Cole's figure, 

 this would seem to be an error. 



The buccalis ampulla? are found in three groups, two inner- 

 vated by the inner buccal nerve of Cole's descriptions and one 

 by the outer buccal. The dorsal group of inner buccalis ampulla? 

 lies on the dorsal surface of the snout, internal to, or slightly 

 posterior to, the occipital and supraorbital groups of ophthal- 

 micus ampulla?, and, like those ampulla?, between the two layers 

 of the subepidermal membrane, these ampulla? having approxi- 

 mately the position of the posterior group of supraorbital ampulla? 

 of Cole's descriptions. The tubules of these ampulla? run 

 postero-ventrally, internal to the ophthalmicus ampulla? and 

 tubules and between the two layers of the subepidermal mem- 

 brane, and with one exception they all open on the external 

 surface in the space included between the latero-sensory canals 

 innervated by the inner and outer buccalis nerves of Cole's 

 descriptions, the former canal being the one to which I have 

 a.bove referred as the suborbital canal. Nine of these pores form 

 a sub-group which lies in the dorso-posterior corner of that space, 

 while one of them opens somewhat ventro- anterior to that sub- 

 - group ; and associated with the tubules of these pores there is 

 the one exceptional tubule, which opens by an isolated pore that 

 lies posterior to the posterior hyomandibular latero-sensory 

 canal of Cole's descriptions. A second sub-group, of seven large 

 pores, lies immediately ventral to the inner buccalis suborbital 

 canal, in a large bend at about the middle of its length, and a 



Proc. Zool. Hoc— 1917, No. X. 10 



