Cottus cognatus, &c. with Cottus-gobio. . 199 
comparison would do what it has done in the previous cases 
of apparent difficulty, only serve to strengthen our argument. 
But in the female, the membrane surrounding the ovaries. is 
certainly ** very black,” while in our fish it is only dotted with + 
black. Here isa difference ; and to it we can afford to allow 
its full weight, for it is the only one which we can find, either 
external or internal. Is it sufficient to separate the species? 
At the least, we may doubt. 
Here then we may rest the argument, as to the identity of 
the European species with the one which we find in Connecti- 
cut. "Three or four points of apparent difference presented 
themselves; but they were only apparent, and have disap- 
peared, with the exception of one solitary item. What rea- 
son then have we for supposing that fish, which correspond 
80 perfectly, are specifically distinct. If both occurred in the 
Waters of this country, it would seem a matter beyond ques- 
tion that they should be arranged under one name. And 
though their specific identity is an exception to the rule 
which prevails in regard to the fresh water fishes of Europe 
and America, and consequently may be by some considered 
improbable, still the perfect coincidence between the two will 
not allow me to doubt, and I must conclude therefore that the 
Cottus gobio is a native of America and is found in at least 
. One stream in Connecticut. | 
I have thus far attempted to prove but the first point which 
Was proposed. It now remains to be shown that this species 
has been described, as an inhabitant of North America, by 
three authors ; and that they have applied to it two generic, 
and three specific names. We will take the descriptions in 
their chronological order. The first is that of Dr. Richardson. - 
If we examine his account we shall find that tbroughout the . 
Whole of it, his object is to show that his fish is distinct from 
gobio, apparently a very difficult matter, and one in -regard to 
Which he is not able fully to convince even himself. He says 
on comparing his specimens ver) minutely with an English 
VOL. y, | 9 
Vaiss 
