170 ELOPIFORM FISHES 



tip of this boss in the prepared specimen (B.M.N.H. 39439) is spongy, suggesting that 

 it was capped by cartilage. This boss probably received branchial musculature, 

 as does the corresponding ridge in A. vulpes. 



The dentition on the parasphenoid and vomer is very similar in both species, yet 

 there are small differences. The parasphenoid teeth of A. vulpes show a gradation 

 in average size from large anteriorly to smaller posteriorly where they also become 

 more conical in shape. Parasphenoid teeth in A. oweni are constant in shape and 

 size throughout their extent. The vomer of both species bears a small, raised, 

 transversely orientated tooth patch of small needle-like teeth. A specimen of A. 

 oweni (B.M.N.H. 30528) shows this tooth patch to be partially subdivided into right 

 and left halves (Woodward 1901 : pi. 4, fig. 2) suggesting the origin of the undivided 

 condition in A . vulpes from paired elements. 



The quadrate/mandibular articulation of A. oweni lies relatively further forward 

 than in the type-species. The lower jaw is shorter, a feature accentuated by the 

 relatively longer snout. A consequence of the greater suspensorial angle (Gregory 

 1933) is that the horizontal limb of the preoperculum is longer than the vertical limb. 

 In A . vulpes the limbs are of equal length. 



The differences mentioned above are minor and serve only to distinguish A . oweni 

 as a distinct, but closely related species. To determine which is the more primitive 

 is not easy. There are several differences which appear to have little or no sig- 

 nificance in this case, such as the median frontal depression, deeper neurocranium 

 and shorter jugular canal in A. oweni. 



A. oweni appears more specialized than A. vulpes in having a relatively longer 

 snout and a more forwardly positioned quadrate/mandibular articulation. In 

 other features, however, there is a greater resemblance to the primitive Osmeroides, 

 for example, the ornamentation, the ridge at the medial margin of the sub-epiotic 

 fossa and the partially divided vomerine tooth patch. 



The majority of specimens of A. oweni are isolated teeth or fragments of tooth 

 plates, making specific determination difficult, particularly since the teeth associated 

 with the crania described above are poorly preserved. However, if B.M.N.H. 

 P. 1697 (a group of teeth from the Lower Hamstead Beds of the Isle of Wight) is 

 correctly identified, then this species must have extended to the Lower Oligocene 

 (Lattorfian). 



Albula eppsi White & Frost 



1931 Albula eppsi White & Frost : 83-84, 105, figs. 137-14, pi. fig. 8. 

 i960 Albula eppsi White & Frost ; White : pi. 30, fig. 4. 



Diagnosis. See White & Frost 1931 : 83. 



Syntypes. B.M.N.H. P.14628, P.i4628a-b, tooth plates from the Blackheath 

 Beds (Sparnacian), Abbey Wood, Kent, and P.15287 from the same horizon and 

 locality. 



Material. Twenty-three specimens in the B.M.N.H. consisting of fragmentary 

 tooth plates and a small portion of an operculum. 



