The Dipneusti and Crossopterygii 



311 



will be noted that there are some differences in result be- 

 tween the two above observers, but as to possible vegetable 

 food a rich soft vegetation doubtless grew that has left no 

 trace in fossil state. 



But the above collective evidence plainly demonstrates 

 that — like all of its ancestral relatives — Diphirus was a 

 freshwater fish that inhabited lakes and marshes. 



A more complicated history however attaches to Gra- 

 phiiirus, Undina (Figs. 49, 50), Lihys, Coccoderma, and 

 Heptanema. In all past literature, it has been accepted 

 openly or tacitly that these were marine fishes. Even where 

 related genera have been regarded as freshwater, others 

 have been view'ed as marine. Thus Eastman, while es- 

 tablishing a correct organic homology between the fishes of 

 New Jersey-Connecticut, and those of the European Keuper, 

 considers the former to be freshwater, the latter marine. 



Fig. 49 



Fig. 49. Undina penicillata. Restored view of entire fish 

 from Solenhofen slates, one-fifth natural size. (After Kayser). 



Fig. 50. 



Fig. 50. Undina gtilo. Skeletal outline of fish found in Lower 

 Liassic rocks of Dorset in England, one-tenth natural size. (After 

 Egerton). 



