PISCES. 
77 
its name), a heterocercal tail, and beautifully enamelled head- 
bones and scales. Phanerojpleuron , with thin scales, occurs 
in the yellow Upper Old Eed Sandstone of Dura Den, Fife- 
Wall-case 
5. 
Table-ease 
10 . 
Fig. 77. —Restoration of Bitterns valenciennesi, from the Middle Old Red 
Sandstone of Scotland; one-fifth nat. size. (After R. H. Traquair. 
Table-case 10.) 
Fig. 78.— Teeth of Paleozoic Dipnoi. 1. Upper and lower jaws of 
Dipterus valenciennesi , from the Middle Old Red Sandstone of Scot¬ 
land ; nat. size. xx. upper teeth or dental plates; xxx. lower ditto; 
g. upper tooth-bearing bones; n. narial openings. 2. Lower teeth or 
dental plates of Ctenodus cristatus (bone wrongly drawn), from the 
Coal Measures ; one-third nat. size. 3. Lower jaw of Sagenodus 
incequalis, showing teeth, from the Coal Measures ; one-half nat. size. 
4. Part of lower jaw of Palcedaphus insignis, with teeth, from the 
Upper Devonian of Belgium; one-sixth nat. size. (Table-case 10.) 
shire (Wall-case 5), and Scaumenacia in the Upper Devonian 
of Canada (Table-case 10). Ctenodus (Fig. 78, 2) and Sagen¬ 
odus (Fig. 78, 3) comprise large fishes known chiefly by 
fragments from the Carboniferous and Lower Permian of 
