198 
PROFESSOKS T. W. BRIDGE AND A. 0. HADDON 
increase in size with the growth of the body, or, at all events, not to an equivalent 
extent. In specimens of six and twelve inches in length respectively, the bladder 
was exactly the same size in both cases. The mesonephric diverticula are exception- 
ally large, and, in conjunction with the lateral lobes of the liver, entirely exclude the 
outer walls of the anterior chamber from contact with their respective lateral cuta- 
neous areas. 
Copidoglanis albilahris. 
As regards both its air-bladder and skeleton, this species also very closely resembles 
Plotosus canius. In size, however, the bladder is somewhat smaller in proportion to 
the body, and has much thicker walls. There is considerable individual variation in 
the size of the organ in this species. In specimens of approximately equal size the 
air-bladder may be a third larger in some cases than in others, but as a rule any 
increase or diminution in size mainly depends on the variability of the lateral 
compartments rather than of the anterior chamber. 
Cnidoglanis megastoma. 
In this species the skeletal modifications differ but little from those of the two 
preceding genera. The fan-shaped subvertebral process at the anterior end of the 
complex centrum, and the expanded and antero-posteriorly flattened anterior division 
of the modified transverse process, are very strongly developed, and form an almost 
continuous bony support to the anterior wall of the air-bladder. The posterior 
division of the same process, and the transverse process of the fifth vertebra, are 
also greatly produced and expanded, and on each side furnish a stout bony investment 
to the dorsal wall of the anterior chamber. The superficial ossifications extend 
outwards from the sides of the complex centrum as broad bony laminae, and even- 
tually become confluent with the ventral surfaces of the modified transverse processes, 
thus converting the anterior part of the cardinal groove into a complete canal. 
The air-bladder is exceptionally well developed, and has large anterior and lateral 
compartments. Its walls are thick and of a peculiarly lustrous appearance. The 
primary transverse septum is inclined forwards, although not to so great an extent 
as in Plotosus, and its ventral margin is coextensive with the width of the bladder. 
In all other features the organ agrees with that of Plotosus. 
The crescentic process of the tripus is not hooked but broad and thin, and in the 
terminal’ part of its rather open curvature is bent downwards and applied to the 
lateral surface of the complex centrum, reaching almost to the ventral margin of the 
latter. 
