FOSSIL AND RECENT 



"5 



asp 



soc 



Fig. 55. Osmeroides latifrons Woodward. Neurocranium in dorsal view. 

 Based on B.M.N.H. P.10465. 



views (Text-figs. 55 and 46, 56 and 47, 57 and 48), the differences in proportion are 

 obvious. The significant features of the neurocranial roof are : the narrow, slightly 

 elongated snout, the broad otic region, the irregular shape of the parietals and the 

 long dermethmoid. The dermethmoid shows a prominent median ridge which is 

 continued posteriorly on the frontals. At the anterior end of the dermethmoid there 

 are inclined struts of bone connecting the horizontal and vertical portions of this 

 element ; in this the dermethmoid resembles that of albulid and pterothrissid fishes. 

 The frontal of 0. lewesiensis is flat throughout but in 0. latifrons the centre of ossi- 

 fication is raised and there is a shallow trough developed anteriorly, features seen 

 in the albulids and, to a lesser degree, in the pterothrissids. 



The supraoccipital of 0. latifrons is relatively small and there is a small, deep 

 depression on either side of the weakly developed crest. The sub-epiotic fossa is 



