Nos. IAND2.] ANATOMY OF SCOMBER SCOMBER. i>jg 



supraobital canal, so prolonged posteriorly, has fused with the 

 supratemporal commissure. This posterior part of the supra- 

 orbital line in these three fishes seems to be represented in 

 Necturus by the four organs said by Piatt to be innervated by a 

 separate dorso-posterior branch of the ophthalmicus facialis (No. 

 55, Fig. 31). In certain teleosts the pit line seems, from Sage- 

 mehl's descriptions (No. 66, p. 508), to be enclosed, as it is in 

 Chim(Era, and to fuse with the so-called supratemporal commissure 

 of the fish ; but this commissure, in the fishes referred to by Sage- 

 mehl, is said by him to lie in the parietal bone and not in the ex- 

 trascapular ones, and hence not to be the homologue of the com- 

 missure in Amia. 



Regarding the middle one of the three sections of the supra- 

 orbital canal of Chinicera Cole suggests, in explanation of its 

 innervation, that certain fibers of the lateralis facialis have become 

 secondarily juxtaposed to the profundus trigemini, thus appear- 

 ing as, but not in reality being, a part of that nerve. As the supe- 

 rior branch of the nervus oculomotorius and the nervus trochlearis 

 both seem, from their distribution, as given in Cole's figure, to 

 lie between the two nerves concerned, such a secondary juxtaposi- 

 tion seems to me wholly impossible, as already fully set forth in 

 discussing these same nerves in elasmobranchs in general in my 

 earlier work (No. 4, p. 539). For similar reasons a simple 

 juxtaposition of lateral fibers coming from the buccalis facialis 

 seems impossible, the nervus opticus lying between the two nerves 

 concerned. The only proper explanation, if the observation be 

 correct, seems to me to be that lateral sensory fibers may, in certain 

 animals, be associated .with the nervus profundus trigemini in ex- 

 actly the same manner that they are associated with other branches 

 of the nervus trigeminus, and as they are also associated with the 

 roots and branches of the facialis, glossopharyngeus and vagus. 

 The development of the profundus in Necturus, a.s given by Piatt ; 

 the statement, by the same author (No. 55, p. 530) that certain 

 organs of the infraorbital of Necturus are in part innervated 

 by branches from the profundus; and van Wijhe's statement (No. 

 79, p. 21) that a branch of the same nerve inPristiurus innervates 

 a part of the supraorbital line of that fish, all certainly indicate this. 



As to the development of the profundus, Piatt says (No. 55, 



