Pboc. Zool. So( 



I. E L A S M ( 



fiKNErtAL FeATUR 



Br 



(TRES OF THE CaNALS AND 

 UA^'CnES. 



'B 



Th;: cavuls usuallj^^ 

 open groove au( 

 They are partly 

 Hepfabranctuas 

 lachus, Hvterodom 



[To face T^. 888. 



EOSTEOIDEI. 



3y scales, and pass through 



Occipital cjmniissui 



Branching genera 



fine dendritic 



the Lateral can 



uauals and brai 



. veniral surface, e 



Cluster and primiti 



ire present, also in frontals 

 d in ethmoid {Polyptertis). 



ng profuse in Lepidosteus. 

 m the Lateral canal. 



Accessory sensory 

 canal-system. 



tive pores usually few. 

 )ry organs. 



1. Lateral Cdnal. 



2. Main Canal. 

 ganglion and 



3. Occipital Comrn 



ganglion. 



4. Hyo-mandlhula 



hvo-mandibu] 



5. Siipra-orbital I 



thalmicus suf 



6. Sub-orbital bra\ 



The Glossopliary 

 does not enter i 

 caual-systeni. 



IV. T E L E O S T E I. 



GE.NEKAL Features of the Canals and 

 Branches. 



Canals sometimes dermal {Amiurtis) or pro- 

 tected by scales or drain-pipe-like canal- 

 bones, or represented only by .sensory organs, 

 or both absent ( Odrmiions, Ccntriscu.i). In 

 some cases {('orist the canal passes through 

 modified scales only. In Exocetus the Late- 

 ral canal passes dorsal to the pelvic fin and 

 ventral to the pectoral, the canals of either 

 side converging ventrally. In Conger, Solca, 

 itc, saccular dilatations pass ofi" from the 

 canals. In the deep-sea Teleosts, e. g. 

 Cottus baihybius, Liparis micropus, Ly codes 

 murcena, &c., the canals are in the form of 

 open grooves. In some Pleuronectidae 2 or 

 3 lateral canals. In Mugii 'J are present 

 {M'DonnelC). 



Occipital commissure neai-ly always present, 

 sometimes one iu froutal region. 



Dendritic branching occasionally present. 



Cluster and primitive pores few, where 

 present. 



Accessory sensory organs sometimes occur 

 (Amiurus, &c.). 



NERVATION'. 



X. Vagi lateralis. 



Innebv.ation. 



I. Lateral Canal. X. Vagi lateralis. In 

 the Ostracions the vagi lateralis is more 

 or less rudimentary (tiiinther). 



'2. Main Canal. V. Ramus ophthalmicus 

 superficialis, the ramus oticus sometimes 

 (Amiurus) ; the glossopharjngeal may 

 either innervate a portion or the whole. 

 The vagus niav or may not by anterior 

 branches supply the initial portion of the 

 main canal. 



nissure. Branch from X. 3. Occipital Commissure. Glossopharyngeal. 



X. Branch from vagi 

 Glossopharyngeal, and V. 



bular branch. VII. Eamus 

 laris. 



iranch. VII. Bamus oph- 



'lerficiilis. 



4. Operculo-mandibidar branch. VII. Bamus 



hyo-mandibularis. In Amiurus, ramus 

 oticus and ramus mandibularis (V.). 



5. Supra-orbital branch. V. Eamus oph- 



thalmicus superficialis. 



nch. Til. Ramus buccali 



Sub-orbital brajwh. V. 

 and ramus maxillaris. 



Ramus buecalis 



