1889.] MR. A. S. WOODWARD ON BUCKLANDIUM DILUVII. 209 
fused together, and the superficial tubercular ornament is so sparse 
and exhibits so indefinite an arrangement, that not even an approxi- 
mate determination of the original sutures can be attempted. The 
only noteworthy feature is the complete absence of tubercles upon a 
narrow longitudinal area (_fv.) inthe median line commencing some- 
what in advance of the supraoccipital, gradually widening in 
front, and evidently passing into an elongated frontal fontanelle. 
The hinder margin of the cranial roof is not much broken, and so 
displays the posterior extent of the supraoccipital; but the only 
portion of the lateral margin is the superior border of the right orbit 
(ord.), which is interesting as showing the forward position of the 
eye. Seen from beneath, a kind of sudden thickening of the roof- 
bones is observed to commence at a short distance behind the orbit, 
producing the appearance of a deep fossa anteriorly; but no precise 
information can be obtained as to the characters either of the brain- 
case or the otic bones. 
The displaced base of the skull and the anchylosed vertebre are 
too imperfect for description ; but the basioccipital and parasphe- 
noid appear to be narrow (fig. 3, ps.), while the side-walls of the 
skull rapidly slope upwards. At the union of the basioccipital with 
the anterior vertebree (ar.) there is a broad downwardly-directed 
angular process of bone ; and the furrow along the inferior aspect of 
the anchylosed centra (v.) is shallow. 
The posttemporal bone (figs. 1, 2, pt.), though firmly fused with 
the cranium, is sharply separated by suture from the anterior upper 
angle of the clavicle; it is broad throughout its length, gradually 
expanding towards its distal articulation. The pectoral arch is best 
preserved on the right side, though even here only fragments of the 
ornamented dermal plate of the clavicle remain; and the articular 
facettes for the spine, equally with the infraclavicular plates, are 
mutilated beyond precise recognition. The clavicular element (el.), 
evidently comprising, as usual, the supraclavicle of ordinary Teleos- 
teans, is about twice as deep as broad and does not taper, but rather 
expands inferiorly. Its lower boundary is arched and seems to have 
projected over the base of the pectoral spine; a thin flat plate of bone 
extends directly inwards from the lower half of its curved front 
margin ; and a more robust bony plate similarly proceeds inwards 
from the lower half of the hinder margin and bulges postero-inferiorly 
in such a manner as to suggest its being an upward extension of the 
infraclavicle (?.cl.). 
Such being the characters of the fossil, it obviously resembles the 
skull and pectoral arch of recent Siluroids with sufficient closeness 
to be placed in that great group of Teleostei. Without a knowledge 
of other portions of the fish, however, it is impossible to determine 
the precise affinities of Bucklandium in the usual manner. It must 
suffice merely to compare the specimen with the skulls of various 
recent genera, and thus arrive at an approximate determination. 
So far as the writer has been able to observe, the London Clay 
genus most closely approaches the living Auchenoglanis of the Nile 
and West-African rivers; and a reduced side view of the head, ante- 
