98 



Crossopterygii. 



Order I. — Crossopterygii. 



Wall-cases "^^^^ fringe-finned fishes, oi* Crossopterygians, are now 



Nos. 5 to 7,' almost extinct, being represented only at the present day by 



and Table- ^ Pohjpterus (Fig. 13G) and Calamoichthys of the African rivers. 



ase, o. o. j^ ^j^^ Devonian and Carboniferous periods they existed in 



KiG. 13G. — f'ohiptervx liirhir, living in tlie Nile, Ganibi:i, etc. 

 ((, pectoral tin; o, pelvic lin; c, anal nn. 



laro^e numbers and in much greater variety. Holoptycldiis (Fig. 

 137) is an Upper Devonian genus from Scotland and Russia, 

 with long and acutely-lobate pectoral fins, obtusely-lobate pelvic 



Fig. 137. — Holopl.i/chiva ; U. Old Red Sandstone, 1-ifesliire (restored by Huxley), a, paired 

 pectoral fins ; b, pelvic fins ; <; the anal fin ; d, anterior dorsal fin ; e, posterior dorsal fin. 



fins, and thick, round, deeply oveidapping scales. Glyptolejds, 

 from the Lower Old Red Sandstone of Scotland, and apparently 

 from the Upper Devonian of Canada, is a nearly identical 

 genus. Glyptolremus (Fig. 138), fi^om the Upper Old Red Sand- 

 stone of Dura Den, Fifeshire, has more obtuse pectoral fins and 

 rhombic scales. Osteolepis (Fig'. 139), Dijjlopteriis, Thursius 

 (Devonian), and Merjalichthijs (Carboniferous and Lower Per- 

 mian) are another group of genera witli enamelled rhombic 



Fig. 138.' 



-Glijptohvuiv.s Kimudrdl, IIuxl. (re.'stored by Huxley) ; U. Old Red Sandstone, 

 Scotland. 



