THE CKAMAL NEKVES AND LATERAL SENSK ORGANS OF FISHES. 219 



Plate 22. 



Fig. 2. Dissection from the left side of Gadns virens, showing the innervation of tlie sensoiy canals. 

 The latter are coloured in segments, to indicate the positions of tlic skeletal supports. The 

 lateral line nerves are shaded. Natural size. 



A. Articular portion of hyomaudibular canal. 



B. Buccal lateral line nerve. 

 B'. Outer Imccal nerve. 



B". Otic branch of same. 



B\ Branch of outer buccal to pit organ. 



£'. Inner buccal nerve. 



B". Upper ramus of same. 



5". Branches of upper ramus to pit organs of snout. 



B^. Lower ramus of inner buccal. 



B". Branch of above to pit organs below infra-orbital line. 



Cb. Cerebellum. 

 C.H. Cerebral hemisphere. 



Cn. Outline of cornea. 



D. Dentary portion of hyomaiidibuhir canal. 

 D.F. Anterior extremity of dorsal fin. 



Fx. Frontal portion of suiira-oi'bital canal. 

 Fj?'. Frontal portion of infra-orbital canal. 

 H. Hyomandibular nerve trunk. 



H\ Anterior or larger division of same. 



//^ Posterior or smaller division of same. 



H^. Chorda tympani nerve (= prte-branchial or pra;-spiracular — facial). 



H\ Hyoidean nerve {= internal mandibular, or post-branchial, or post-spiracular) . 



H^. External mandibular lateral line nerve. 



H^. Posterior branch of same to sense organs 11 and 12 of the hyomandibular canal. 



H\ Anterior branch of same to facial and mandibular pit organs. 

 H.C. Hyomandibular sensory canal (violet). 



I.e. Infra-orbital sensory canal (red). 

 L. Lateralis lateral line nerve. 



L\ Supra-temporal branch of above. 



L-. Posterior division of supra-temporal branch to sense organ 4 of the lateral canal, &c. 



L^. Dorsal division of supra-temporal branch to sense organs 1 and 2 of the lateral canal, &c. 



L'. Anterior division of supra-temporal branch to sense organ .'3 of the lateral canal, &c. 



L''. Doisal ramus of lateralis nei've. 



L^. Dorsal forward branch of same. 



U. Ventral ramus of lateralis. 



L.C\ Supra-temporal portion of lateralis canal. ) 



T /-.. T + 1 I 1-- 1 i- r 1 r = Lateralis sensory canal (brown). 



L.t . Lateral portion or lateralis canal. j . J \ i- 



L.G. Giinglion of superficial oplithahnic, buccal, and external mandibular lateral line nerves. 

 L.l. Lobus inferior. 

 L.O' ". Lateral line ossicles 1 to 3 supporting the lateralis canal. 

 Mb. Medulla oblongata. 



Mif. Third or mandibular or inferior maxillary division of tlu^ trigeminus. 

 Mx. Second or maxillary or superior maxillary division of the trigeminus. 

 SECOND SERIES. — ZOOLOGY, VOL. VII. 30 



