URENCHELYS. 31 



covered in tlie Engiisli Chalk. The Latter fossils are provisionally ascribed to 

 JJrencliehjs on account of their dentition and their general resemblance to the 

 corresponding parts of the species from the Lebanon. 



1. Urenchelys anglicus, A. S. WoodAvard. Plate IX, figs. 1 — 3. 



1900. JJrencliehjs aiujlicus, A. S. Woodward, Anu. Mag. Nat. Hist. [7], vol. v, p. 321, pi. ix, fig. 1. 



1901. Urenchelys anglicus, A. S. Woodward, Catal. Foss. Fishes B. M., jjt. iv, p. 339. 



T!/2)e. — Imperfect head from a Turonian zone ; Willett Collection, Brighton 

 Museum. 



Specific Characters. — An imperfectly known and comparatively large species, 

 the skull attaining a length of about 7 cm. Head much deeper in proportion to its 

 length than in the type species. 



Description of Specimens. — The type specimen is the only nearly complete head 

 yet discovered, and is represented of the natural size from both sides in PI. IX, 

 figs. 1, 1 a. The information it affords is partly confirmed, partly supplemented by 

 two other fragments evidently of the same species in the British Museum. 



The cranium is shown to be very narrow and elongated, and its constituent 

 bones are remarkably stout. Its roof in the parietal and frontal regions rises into 

 a sharp median longitudinal ridge, and the occipital border is also raised. The 

 parietal bones {pa.), as usual, meet in the middle line, but the shape of the suture 

 between these and the frontals is uncertain. The squamosal bone on each side 

 (PL IX, fig. 2, S(p) is traversed by a deep longitudinal slime-canal and extends in a 

 slender pointed extremity nearly as far forwards as the anterior end of the frontals. 

 The alisphenoidal ossification {as) is seen below. There is a sharp post-orbital 

 prominence (fig. 1, sp.), evidently formed by the cartilage-postfrontal or sphenotic. 

 The precise shape of the ethmoidal rostral region (fig. 1, eth.) is not shown in 

 either of the known specimens ; but its total length seems to be about half that 

 of the whole cranium. A displaced stout bar of bone on the right side of the type 

 specimen above the maxilla is probably the parasphenoid {yas.). 



The mandibular suspensorium is well displayed on each side of the type speci- 

 men. The upper articulation of the expanded hyomandibular {Jmi.) extends as far 

 forwards as the sphenotic; and the articular end of the quadrate {qu.),iov the 

 support of the mandible, is directly beneath the same element. The pterygoid 

 arcade (PL IX, fig. 3, pt.) is very delicate and toothless, and quite short, as usual 

 in eels. The maxilla (fig. 1, mx.) is especially stout; and this element is displaced 

 both on the left side of the type specimen (fig. 1 a, mx.) and in B. M. no. P. 4510 a, 

 (fig. 2, mx.) so as to expose its oral face, which is expanded, slightly concave, and 

 marked with the bases of attachment of clustered small teeth. The premaxillfe 



