Plate II. — Continued. 



Fig. 20. Dinichthys lincolni Claypole. Marcellus shale (Erian 

 division of the Middle Devonian) ; Geneva, Ontario county, New 

 York. Right vomerine tooth seen from the inner side and 

 slightly from in front. Along the anterior face is seen a longi- 

 tudinal fracture due to mechanical deformation; above and be- 

 hind is the stout process serving for attachment of the tooth. 

 Holotype in New York State Museum. Page 193 



Pig. 21. Dipterus digitatus, sp. nov. State Quarry beds (Up- 

 per Devonian) ; North Liberty, Johnson county, Iowa. Right 

 mandibular plate of a fully grown individual. A photograph 

 of the same specimen is reproduced in Plate VII, fig. 25. Com- 

 pare with the series of palatal dental plates belonging to the 

 same species, and shown in Plate VII, figs. 20-24. Page 221 



302 



