98 FISHES AND FISH DEVELOPMENT—PIERS. 
A YounGc SILUROID. 
A plate in the report of the Fishery Commission for 1885 
(Part XIII), illustrating a paper on the development of osseous 
fishes, by John A. Ryder, directed attention to a curious speci- 
men in the Museum collection which had been exhibited at the 
London Fishery Exhibition of 1885. This was a young Cat- 
fish, with the yelk-sack still attached, but in a very advanced 
stage of development. 
Description :—Skin smooth and shining. Lateral line dis- 
tinct, convex under the dorsal and then straight. Body com- 
pressed. Head depressed, on the top of which is a curious five- 
lobed figure, lighter than the surrounding colour, which is prob- 
ably the cartilaginous bones beneath showing through the semi- 
transparent skin. There are six discernible barbels, which are 
arranged as follows: One on the upper side of each angie of 
the mouth, and four arising at nearly equal intervals under the 
lower jaw. Anterior to each eye is a minute knob or flap, which 
may or may not be an undeveloped nasal barbel. The yelk-sack 
is sub-globular, slightly flattened on its under side, and having 
its greatest measurement longitudinally. On this the median 
ventral vessel appears as a raised line, which, as branched vitel- 
line capillaries, arises from underneath, and thence, after passing 
over the anterior end, bends backwards on its way to the heart. 
First dorsal fin sub-quadrate, third ray longest. The spine 
not serrated. This fin arises just posterior to the pectorals. 
Second dorsal or adipose fin long, rounded on its upper margin, 
its height to its base as one to six. 
Pectorals pointed with the posterior margin rounded. The 
spine being its greatest length. 
Ventrals moderately broad and rounded. 
Caudal forked with sixteen complete rays. Accessory rays 
present. 
Colowr :—The fish proper is flesh-coloured, but lighter on the 
head. A light ash-coloured spot on each side shows the position 
of the air-bladder. Pupil white ; iris bluish-black. 
The yelk-sack is flesh-coloured, but of a darker shade than 
