324 Mr. A. S. Woodward on a new 



XLV. — On a new Specimen of the Glapeoid Fish Aulolepis 

 fypu8>om the English Chalk. By A. Smith Woodward, 

 F.L.S. 



[Plate IX. figs. 2, 2 a.] 



When describing the Cretaceous Clupeoid fish Aulolepis 

 typus, Ag., five years ago*, I referred to this species one 

 specimen in the British ]\luseuin (no. P. 1854) which had 

 aheady been h^bellod as belonging to it by Agassiz. This 

 fossil showed a considerable portion of the skull, and proved 

 to be identical with two other specimens in the British 

 Museum displaying the head in a still better state of preser- 

 vation. Tlie latter (nos. 49903, P. 5681) were thus deter- 

 mined as also belonging to Aulolepis typus^ and the characters 

 of the cranial roof and branchiostegal ap]:)aratus were both 

 desciibed and figured. It now apjjears from a still more 

 satisfactorily preserved specimen, undoubtedly of this species, 

 in the Woodwardian ]\luseum, Cambridge, that the three 

 fossils just enumerated were wrongly ascribed to the fish in 

 question. The skull therefore needs an amended description, 

 and the new facts necessitate a reconsideration of the precise 

 systematic position of the genus Aulolepi><. 



The Woodwardian fossil was obtained from the Lower Chalk 

 of Southerara, near Lewes, and, thanks to the kindness of 

 Prof. McKenny Hughes and Mr. Henry Woods, I have had 

 the privilege of studying it in connexion with the British 

 Museum collection. 



The cranium is well exposed from above (fig. 2 a), and 

 some of the principal sutures are distinct. The suj)raoccipital 

 bone {s.occ.) is relatively small, with a median vertical crest 

 on its hinder face. Its upper portion enters the cranial roof, 

 but does not completely separate the parietals [pa.], wiiich 

 are much extended antero-posteriorly and meet in the middle 

 line for more than half of their length. The squamosal- 

 pterotic region {sq.) also seems to be relatively large, but is 

 not in the same plane as tlie parietals, sinking into a fossa 

 which deeply impresses the hinder portion of the cranial roof 

 on either side. The frontals (//-.) are very large, widest in 

 the interorbital region and rapidly tapering in front, where 

 the small mesethmoid [m.) projects beneath them. None of 

 these bones are ornamented. Uf the cheek-plates only part 



* Proc. Zool. Soc, 1894 (1895), p. 660, pi. xliii. figs. 2-6. 



