24 



PISCES 



CLASS I 



pterygium of pelvic fins segmented, fringed on one side with a series of carti- 

 laginous rays, and continued behind into the spine-shaped clasper in the male. 

 Two small anal fins, directly supported by the haemal arches. Caudal fin 



Fig. 41. 



c 



\l*"^ 



Fig. 42. 



Pleuracanthus (Orthacanthus) 

 bohemicus, Fritsch. Lower 

 Permian (Gas -Coal); Krot- 

 schovv, Bohemia. A, Side 

 view. B, Hinder view. C, 

 Transverse section. Natural 

 size. 



Pleuracantlnis (Xenacanthus) decheni, Goldf. Lower Permian; Braunau, 

 Bohemia. x% J, Anterior portion of fish. B, Detached teeth, magnified 

 (after F. Roemer). 



Fig. 43.' 



Pleuraco.nthu* {Diflodvs) lo- 

 hemicus, Qnenst. Teeth in 

 side view (^4), and hinder 

 view (B). Lower Permian 

 (Gas - Coal) ; Nyfan, near 

 Pilsen, Bohemia. Natural 

 size. 



separated both from the anals and from the dorsal. Skin probably destitute 

 of shagreen. 



Complete skeletons are known from the Rothliegenden of Lebach, near 

 Saarbrucken, in Rhenish Prussia, and of Braunau and Ruppersdorf in Bohemia; 

 from the Lower Permian Gas-Coal of Bohemia ; from the Coal Measures of 

 Commentry in France (Fig. 40) ; and from the Lower Hawkesbury Formation 

 of New South Wales. Complete skulls have been found in the Coal Measures 



