324 Mr. A. S. Woodward on a new 



XLV.— 0« a new Specimen of the Clupeoid Fish Aulolepis 

 typus/rowi theEnglhh Chalk. By A. SxMiTH WOODWARD, 

 F.L.S. 



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



When describing the Cretaceous Clupeoid fish Aulolepis 

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

 s|)ecimen in tlie British Museum (no. P. 1854) which had 

 already been labelled 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 

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

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

 mined as also belonging to Aulolepis typus^ and the characters 

 of tiie cranial roof and branchiostegal apparatus were both 

 desciibed and figured. It now appears from a still more 

 satisfactorily preserved specimen, undoubtedly of this species, 

 in the Woodwardian Museum, Cambridge, that the three 

 fossils just enumerated were wrongly ascribed to the fish in 

 question. The skull therefore needs an amended descriptioUj 

 and the new facts necessitate a reconsideration of the precise 

 systematic position of the genus Aulolepis. 



TheAVoodwardian fossil wasobtained from the Lower Chalk 

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

 Prof. j\lcKenny Hughes and Mr. Henry Woods, I have had 

 the privilege of studying it in connexion with the British 

 jMuseum collection. 



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

 some of the principal sutures are distinct. The supraoccipital 

 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.), which 

 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 the 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. (Jf the cheek-plates only part 



* Proc. Zool. Soc. 1804 08i>-5), p. GC<0, pi. xliii. figs. 2-6. 



