28 



FOSSIL FISHES. 



Platysomus (Fig. 44), JEurynotus (Fig. 45), Wardichthys, Cheiro- 

 dus (Amphicentrum) (Fig. 4G), Mesolepis, Benedenius, JZurysomus, 

 are placed here, and perhaps also Dorypterus. 



Fig. 44. — Platysomus strict us, Agassiz (restoration after Dr. R. H. Traquair), Magnesian 



Limestone. 



3. The Lepidosteoidci, illustrated by the recent Lepidosteus, or 

 bony pike of North America, were abundantly represented in 

 Mesozoic times by a large series of fishes ; embracing the Sauriace, 

 the Sphcerodontidtf, the Dapediidce (or Stylodontidce), the Aspi- 



FlG. Vo.—Eurynotv.s crcnatas, Agassiz, "Cement-stones, ' Carboniferous Series of Scotland 



(after Traquair). 



dorliyncliidce, and the Pycnodontida (Fig. 48); having rhombic 

 ganoid scales and semi-heterocereal tails ; the vertebrae were less 

 ossified than in the recent Lepidosteus, and in all the notochord 

 was more or less persistent. In the Pyc?iodo?itidce the mouth was 



