130 
my disposal, for comparison with my specimens, and also 
to L. C. Miall, Esq., who identified the labyrinthodon t 
remains. 
ELASMOBRANCHS. 
Gtracanthus formosus. Ag. 
G. TUBERCULATUS. Ag. 
Pectoral and dorsal spines of this genus are frequently 
found. The bones of the pectoral arch are also met with, 
and occasionally patches of shagreen covered with small 
tubercles. 
The gyrating lines of Formosus are occasionally found 
divided into tubercules, which are the characteristic of the 
second species, Tuberculatus ; but as the various intermediate 
stages can be traced in a series of the spines, I infer there 
can be no sufficient grounds for considering the latter more 
than a variation from the original typ e. 
Cten ACANTHUS HYBoiDEs. Egerton. 
Tolerably abundant. In good state of preservation, 12 
to 15 inches in length. 
Ctenacanthus sp. 
Straight, ridges much broader than in C. hyboides 
and much fewer in number, having only 5 or 6, whilst 
C. hyboides has 16 or 18. The spine presents a fibrous 
appearance, as though the ganoine had been dissolved away, 
exhibiting the bony structure beneath. Its length is 4 to 6 
inches. 
Ctenacanthus sp. 
This spine difiers from the preceding in being more 
curved. The ridges being symmetrical and not running or 
branching into each other, and being closer and finer in 
appearance. 
