122 ELOPIFORM FISHES 



two of these similarities would not exclude 0. latifrons from the ancestry of the 

 Pterothrissidae since the position of the lower jaw articulation varies within each 

 albuloid family and a broad parasphenoid is a basic albuloid character, also found 

 in the primitive Osmeroides lewesiensis. The shape of the parietals, however, is a 

 character of the Albulidae not found in the Pterothrissidae. This similarity is noted 

 here, but no conclusions are drawn, as the phylogenetic implications of parietal shape 

 are not understood. 



Genus DINELOPS Woodward 

 1907 Dinelops Woodward : 121. 

 Diagnosis. See Woodward (1907 : 121). 

 Type and only species. Dinelops ornatus Woodward. 



Dinelops ornatus Woodward 

 1907 Dinelops ornatus Woodward : 121 , pi. 24, figs. 4-6. 

 Diagnosis. See Woodward (op. cit.). 



Holotype. B.M.N.H. 39432, an incomplete cranium from the Upper Cenomanian 

 of Kent. 



Material. Only three specimens are known, the holotype and the paratypes 

 B.M.N.H. 49091 and P.1812. The specimens consist of incomplete cranial remains 

 and parts of the trunk from the Lower Chalk of S.E. England. 



Remarks. The affinities of this genus are problematical. Woodward (1907) 

 stated that Dinelops resembled Osmeroides, a view which, with reservation, is upheld 

 here. 



The skull roof is relatively broad above the cranial vault but tapers sharply 

 immediately anterior to the level of the autosphenotic spine, as in Osmeroides 

 latifrons. The roofing bones are ornamented with coarse rugae which, unlike any 

 species of Osmeroides, extend on to the dermethmoid. Above the cranial vault 

 there is a median frontal depression but it is weakly defined. A medial branch of 

 the supraorbital sensory canal opens on to the surface of the frontal above the hind 

 end of the orbit and continues forward in a shallow trough, a condition similar to that 

 of Albula. 



The supraorbital, as in Osmeroides, is large and ornamented posteriorly. 



The orbit is relatively large, larger than in any species of Osmeroides, and sur- 

 rounded by a series of six canal-bearing infraorbitals. The sixth member, the 

 dermosphenotic, is known by small fragments. The bones are thin, as in Osmeroides 

 latifrons, and devoid of ornamentation. The posterior infraorbitals are wide, as in 

 Elops, but the fourth is distinctively very shallow. 



Of the upper jaw only the maxilla is known. It is totally unlike that of Osmeroides. 

 The maxilla is straight and extends back to beneath the centre of the posterior infra- 

 orbitals. Anteriorly the maxilla is narrow and bears a prominent palatine cup 



