io8 Evolution and Distribution of Fishes 



Fig. 7. Conodonts and cyclostomatous teeth, a. b. external and internal 

 labial teeth, Petromyzon fluviaiile; c, d, e, conodonts (from Newberry and 

 Hinde) ; /, maxillary tooth-plate, Geotria australis; h, do. G. chilensis; g, 

 tooth-plate of Conodont (from Newberry) ; i, mandibular tooth-plate, G. 

 chilensis; k, I, conodont tooth-plates (from Newberry and Hinde) ; m, tooth- 

 plate, Petromyzon marinus ; n, 0, conodont tooth-plates (from Newberry and 

 Hinde) ; p, lateral tooth-plate, Myxine gliitinosa; r, do. of conodont. Poly- 

 gnathus (from Hinde). All enlarged. 



