﻿PLATE I. 



Fig. 



1. Restored figure of Palceoniscus macropomus, Agassiz. 



2. Diagram of the bones of the head (restored) of Palceoniscus macropomus : p. parietal ; 



f. frontal ; sq. squamosal ; e. super-ethmoidal ; a.f. anterior frontal ; p. mx. prae- 

 maxilla ; mx. maxillse ; s. o. suborbitals ; d. dentary ; ag. angular ; op. operculum ; 

 p. op. praeoperculum ; i. op. interoperculum ; br. branchiostegal rays ; s. t. supra- 

 temporals (?) ; p. t. post-temporal ; cl. clavicle ; p. cl. post-clavicular ; i. cl. 

 infra-clavicular. 



3. Sketch of the bones of the head of Palceoniscus macropomus, from the Zechstein, 



Ilmenau ; enlarged 3-th, from a specimen in the Edinburgh Museum of Science 

 and Art: li.m. hyomandibular ; pa. palatopterygoid ; q. quadrate; sp splenial. 

 The other letters as in Fig. 2. 



4. Dentary (d.) and splenial (sp.) elements of the lower jaw of Palceoniscus comptus, 



Agass., dislocated ; §rds of the dentary being represented only by the impres- 

 sion of its inner surface, the bone itself with the teeth remaining at the symphysial 

 extremity: enlarged two diameters. From a specimen from Thickley, Durham, 

 in the Collection of the Earl of Enniskillen. 



5. Bones of the shoulder-girdle of Palceoniscus, restored. Lettering as in Fig. 2. 



6. Sketch of the arrangement of the branchiostegal rays in a specimen of Palceoniscus 



comptus in the Museum at Newcastle. 



7. Sketch of the bones of the cranial shield of Nematoptycldus Greenoclcii, Agass., sp. ; 



natural size : p.f. posterior frontal. The other lettering as in Figs. 2 and 3. 

 From a specimen from Wardie in the Collection of the Author. 



8. Front view of the same specimen ; slightly enlarged : n. nasal openings. Other 



lettering as above. 



9. Dentary bone of NematoplycMus GreenocMi ; natural size. From a specimen in the 



Collection of Dr. Hunter, Braidwood, Lanarkshire. Most of the bone has flaked off 

 and left behind an impression only of the inner surface ; some of the laniary teeth 

 remain on the upper margin, but are split through vertically ; on the anterior 

 extremity some of the minute external teeth are seen, the large ones being here 

 concealed. The position which would be occupied by the angular (ag) and 

 articular (ar.) is indicated in dotted outline. 



10. Splenial bone of Nematoptycldus GreenocMi^ from the outer or aboral side; natural 



size. Collection of the Author. 



11. Restored outline of the head of Nematoptycldus Greenoclcii. Lettering as in Fig. 2. 



