1893.] 



OSTEOLOGY OF LEPIDOTUS AXD DAPEDIUS. 



5G1 



The membrane-bones o£ the cranial roof do not extend bac-k\Aards 

 quite so far as the occipital border, the narrow space thus left 

 being covered by the supratemporal plates. There are two prin- 

 cipal pairs of bones, the short 'parietals (Plate XLIX. fig. 1, pa.) 

 behind, and the longer frontah (fr.) forwards, not bilaterally 

 symmetrical, and uniting in all directions by very irregular an- 

 gulated sutures. More anteriorly there would be the nasals, but 





Head-bone3 of Lepidoius lafifrons ; Oxford Clay, retcrboroiigh. 

 One half nat. size. 



1. Exoccipital. 2. Pro-otic. 3. Parasphenoid, inferior aspect. 3 «. Pura- 

 spheaoid, superior aspect. 4. Right quadrate, inner aspect. 5, Left 

 quadrate, outer aspect. G. Metapterygoid. 



hpt., basipterygoid process ; /., foramen ; p., process. 



the.se are not satisfactorily known. The long and nari-ow squa- 

 mosal element (*</.) on each side reaches as far forwards as tin* 

 anteritjr extremity of the parietals, but not so far backwards as 

 the hinder margin of tliese bones. It is considerably ()\i'rlap[)t'd 

 behind by the supratt'inporal scries of platcvs, and on the inner 



