ORAL CIRRI OF SILUROIDS AND ORIGIN OF THE HEAD IN VERTEBRATES. 47 



1 Woodward, A. S., Catalogue of fossil Fishes in the British Museum, 1891. 



/ Zincone, Ant., Osservazioni anatoniiche su di alcune appendici tattili dei 

 pesci, in : Rendiconti Accad. Sc. Napoli, 1876. 



ZlTTEL, Handbuch der Palaontologie, V. 3, 1890. 



LETTERING OF FIGURES. 



Cor. p. 



Coronoid piece. 





Pr. orb. c. 



Cor. t. 



Coronoid tentacle. 





Prepal. 



Eph. 



Epiphysial bar. 





Proc. cor. 



H. M. 



Hyomandibular. 





Pty. 



Hy. 



Hyoid. 





Qu. 



1. v. s. 



Lateral tentacle-like 



sup- 



Sty. Hy. 





port of the velum. 





P. cor. 



Mx. t. 



Maxillary tentacle. 





R. md. 



111. V. s. 



Median tentacle-like 

 port of the velum. 



sup- 



P. md. ext. 



Merit, p. 



Mental piece. 





P. md. int. 



Merit, t. 



Mental tentacle. 







Mck. 



Meckelian cartilage, 





P. mx. 



m. Mck. 



Mento - Meckelian 



pro- 



P. ment. 





process. 





P. o. p. 



Na. 



Nasal cartilage. 







Na. t. 



Nasal tentacle. 





P. pal. 



Op. c. 



Opercular cartilage. 





P. pmx. 



Pmx. t. 



Preinaxillary tentacle. 



P. subm. 



Pmx. p. 



Premaxillary piece. 







Preorbital canal. 



Prepalatine cartilage. 

 Processus coronoideus. 



Pterygoid cartilage. 



Quadrate cartilage. 



Stylohyal. 



Ramus coronoideus. 



Ramus mandibularis. 



Ramus mandibularis ex- 

 ternus. 



Ramus mandibularis in- 

 ternus. 



Ramus maxillaris. 



Ramus mentalis. 



Ramus ophthalmicus pro- 

 fundus. 



Ramus palatinus. 



Bamus premaxillaris. 



Ramus submandibularis. 



Plates I., II. 



Fig. 



1. 



Model of Auchenaspis, front view. 



Fig. 



2. 



,, ,, „ side view. 



Fig. 



3. 



,, ,, Silurus, front view. 



Fig. 



4. 



,, ,, ,, side view. 



Fig. 



5. 



,, ,, Trichomyctenis, front view. 



Fig. 



6. 



,, ,, Callichthys, front view. 



Fig. 



7. 



,, ,, ,, side view. 



Fig. 



8. 



Sensory branches of Trigeminus of Auchenaspis. 



Fig. 



9. 



,, ,, ,, ,, ,, Trichomyctenis 



Fig- 



10. 



,, ,, ,, ,, „ Callichthys. 



Fig. 



11. 



,, j) j, >> >5 Myxine. 



