PISCES 



CLASS I 



Uronemus, Ag. (Ganopristodus, Traq.). Body laterally compressed, with 

 small and very thin scales, which are faintly striated. Paired fins acutely 

 lobate. Dorsal fin arising shortly behind the head. U. lobatus, Traq., from 

 Lower Carboniferous (Calciferous Sandstones), Burdiehouse, near Edinburgh. 



Conchopoma, Kner. Lower Permian ; Ehenish Prussia. 



Family 2. Ctenodontidae. Traqiiair. 



on the 

 Jugular 



Ä pair of dental plates on the palatine bones, and an opposing 

 splenials ; these plates usually retaining traces of their component denticles 

 plates usuülly present. Tail diphycercal or heterocercal. 



Dipterus, Sedgw. and Murch. (Catopterus, Polyphradus, Ag.), (Figs. 114, 

 115). Small fishes. Bony plates of head covered with punctate ganoine, 

 but cranium apparently quite cartilaginous. Base of cranium covered with a 



Dipterus valcticiennesi, Sedgw. and Murch. Restoration, i/s »at. size. 

 Lower Cid Red Sandstoiie ; Baniiiskirk, Orkney (after Pander). 



broad, rhombic parasphenoid (PSph), which is flanked on either side by a 

 pterygo- palatine (P) extending forwards into a triangulär pointed plate, 

 which serves as base for a large triangulär tooth (d) bearing tuberculated 

 radiating ridges. The two palatine bones meet in 

 the middle in a straight line. The mandible is com- 

 pletely ossified, with a single, large dental plate on 



PSph 



Dipterus valencienyiesi, Sedgw. and M. Lower Old Red Sandstone ; Banniskitk. A, Roof of skull. li, In 

 perfect palate (PSph, Parasplienoid ; P, Pterygo - palatine, accidentally divided into two pieces behind by 

 broken Ime ; d, Palatine tooth). C, Imperfect mandible with tooth (d), after Pander). 



the splenial of each side, and its tuberculated ridges radiating fan-like froni 



