Ichthyology of the Firth of Forth. 345 
That it is far from being a great rarity I appeal to the authority 
of Sir Thomas Brisbane, who affirms that he has often met with it 
on the west coast of Scotland, inhabiting small pools in company 
with the Pholis Isevis and other kinds of blenny ; to that of Dr 
Johnston, who has noticed its occurrence in Berwick Bay ; to that 
of Mr Couch, as well as that of Mr Jago, as to its existence on the 
coast of Cornwall ; to the frequent discovery of it in the Sol way by 
the fishermen ; (I myself found it once;) and to the fact of three 
specimens having been captured by myself in the Firth of Forth ; 
besides Mr Handcock's discovery of it on the Northumberland coast, 
in May last. Perhaps, the investigation of such species, the authen- 
ticity of which has been doubted, may be as profitable as the search 
after new ones, and may save much trouble and confusion to com- 
pilers in future. 
In appearance this animal little resembles any of our British fishes 
as to shape or colour, and may well be compared, from its form, to a 
frog in the tadpole state, from which circumstance it appears to 
have derived the name of " tadpole fish." 
At the origin of the lateral line are nine or ten small tubercles, 
which are not perceptible when the fish is recently taken ; but when 
the skin is somewhat shrunk by exposure to the sun or open air, 
these gland-like bodies become very evident. 
. This appearance caused Dr Fleming to suppose that the Barbus 
minor of Jago was distinct from Pennant's trifurcated hake, and he 
described it in his work on British Animals as a new species, under 
the name of Raniceps Jago. Dr Fleming was unfortunately misled, 
probably owing to his never having seen the fish, nor perhaps was 
there then in Scotland a preserved specimen in existence to consult. 
This defect I have endeavoured to supply by presenting a perfect 
individual to the museum of the Royal Society of Edinburgh. 
This affords an opportunity of observing how liable we are to be 
deceived when we do not examine specimens in a recent state, and 
how ready our zeal for discovering new objects is to hurry us into 
creating species out of imperfect descriptions. 
It was not till after careful examination that I came to understand 
what these elevations on the origin of the lateral line were owing to. 
At first I imagined they were caused by the elevation of the scales, 
but by the assistance of a glass I observed these tubercles were not 
merely placed on the skin, but that they originated beneath the cu- 
ticle ; while they appear to be small glands for secreting a thick mu- 
cus, with which the whole surface of the fish is covered. 
The colour of the body is a dark sooty black ; that of the lips, 
angle of the mouth, and under the gill- covers, of a pure white. The 
second dorsal, caudal, arid anal fins, are of a deep black, with the up- 
