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PKOFESSORS T. W. BRIDGE AND A. C. HADDON 
In Liocassis there is a well developed post-temporal plate, with a concave posterior 
face, and a thickened and convex anterior surface. To the ventral and inner margins 
of each plate the crescentic extremity of the anterior division of the transverse process 
of the fourth vertebra is applied, precisely aa in Macrones. The air-bladder closely 
resembles that of Pseudobag but relatively to the size of the body, is, perhaps, 
somewhat smaller, the reduction, however, being mainly at the expense of the lateral 
compartments. Both the anterior and lateral chambers have undivided cavities and 
perfectly smooth walls. The primary transverse septum is represented by a stout 
vertical column of fibres, continuous behind with the longitudinal septum, and having 
its dorsal margin attached to the skeleton in the usual fashion. The longitudinal 
septum is complete posteriorly. 
The tripus has but the barest rudiment of a heel-like process, but in all other points 
the Weberian ossicles are in close agreement with those of the type form. 
Bagroides melanoptenis. 
This species is to some extent intermediate between Liocassis micropogon and 
Macrones Hoevenii. In the nature of its skeletal modifications Bagroides closely 
resembles the latter, but as regards its air-bladder the agreement is with Liocassis; 
nevertheless, Bagroides has one or two noteworthy peculiarities of its own. 
Each post-temporal plate is unusually large, and extends inwards along the lower 
border of the inferior limb — with which, of course, it is continuous — nearly as far as 
the articulation of the latter with the basiocclpital. In shape the plate is a somewhat 
ii’regular oval, the long axis of v.Eich is directed from within outwards and downwards. 
The posterior face of the plate is deeply concave, resembling a shallow cup ; its peri- 
pheral margins are exti-emely thin and brittle, but towards the centre of its anterior face 
the plate becomes greatly thickened, and is at the same place perforated by a tubular 
and vertically-disposed socket for the proximal end of the clavicle. The crescentic 
distal extremity of the modified transverse process is much shorter than in Macrones, 
but has the same relations to the ventral and inner margins of the correlated post- 
temporal plate as in the latter Siluroid, or, more particularly, as in M. Hoevenii. At 
the junction of the crescentic process with the much thicker root of the transverse 
process there is a deep groove, which is concave from above downwards, and looks 
forwards and a little outwards ; and into this groove is received a rounded articular 
ridge on the posterior face of the inferior limb of the post-temporal, near the junction 
of the latter with the post-temporal plate. The interlocking articulation of the Iavo 
structures enables the transverse process to afford an exceptionally firm support to the 
shoulder-girdle. The ligament described and figured in Macrones nemurus as passing 
between the transverse process and the post-temporal plate, although present in most 
ot the species so far described, is absent in Bagroides. 
The air-bladder is somewhat pyriform in shape, with the broad end directed for- 
