1889.] MR. A. S. WOODWARD ON BUCKLANDIUM DILXJVII. 20!) 



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 (fo.) in the median line commencing some- 

 what in advance of the supraoccipital, gradu>illy 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 

 \orh.), 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 vertebrsE are 

 too imperfect for description ; but the basioccipital and fiarasj)he- 

 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 vertebrae (wr.) there is a broad downwardly-directed 

 angular process of bone ; and the furrow aloiig the inferior aspect of 

 the anchylosed centra (».) is shallow. 



The posttemporal bone (figs. 1, 2, pt.), though firmly fused with 

 the cranium, is shar[)ly 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, arc 

 mutilated beyond precise recognition. The clavicular element {cL), 

 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 (i.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 oi 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- 



