458 woodward: fossil fishes of the upper lias of whitby. 
original fragments with skulls which are common in the Lower 
Lias of Lyme Regis ; for there is as yet no definite proof of 
the range of any species of fish from the Lower to the Upper 
Lias. The type specimens in question, however, were acquired 
by the British Museum with the collections of the late Earl of 
Enniskillen and Sir Philip Egerton in 1882, and it is thus 
possible now to compare them carefully with ample material. 
Mr. Etheridge has kindly examined them and made such careful 
comparisons, with the result that he considers they must be 
regarded as true Whitby fossils. 
The imperfect Upper Liassic skull which must thus be 
regarded as the type specimen of Belonorhynchus acutus is seen 
in left side-view, as represented in Agassiz's figure {torn, cit, 
pi. xlvii. a, fig. 4), and exhibits the characteristic backward 
extension of the cranial roof. The orbital rim is much broken, 
but the extremely attenuated rostrum is indicated apparently 
throughout its entire length, and there are traces of the 
sharply-pointed large teeth in its anterior portion. As preserved, 
the outer face of the cranial roof is finely punctate and rugose, 
while the ornament on the rostrum tends tow^ards wavy 
longitudinal striations. Where the outer face of the rostrum 
is broken away towards its anterior end, an internal cavity 
filled with calcite is exposed. 
The second specimen noticed and figured by Agassiz 
(pi. xlvii. a, fig. 3) is regarded by him as a fragment of 
a mandible. As, however, this fossil also exhibits a central 
cavity filled with calcite towards its anterior extremity, it is 
probably another example of the rostrum. The degree of 
tapering is approximately as in the former specimen. Assuming 
this interpretation to be correct, the hinder half of the fossil 
and its anterior quarter exhibit the inner face of the right 
side of the snout, while the intervening region is complete and 
a portion of its calcite-core projects in front. There are remains 
of the characteristic teeth, but their size and state of pre- 
servation are exaggerated in the original figure. 
