8 MONOGRAPH OF THE FRESH WATER Il. 
yet been sufficiently explored. We may expect many species from the rivulets of 
the highlands and slopes of mountains, as well as in the valleys; for Pallas cites 
a C. gobio, L. in the lake Baikal and the fresh waters of Siberia; but it is more 
than probable that this is a distinct species. He describes another under the name 
of OC. minutus, which was sent to him by Merk as coming from the fresh waters 
which empty into the Ochotsk sea. It resembles so closely C. gobio, described in 
the Histoire Naturelle des Poissons, that Cuvier himself says that he dares not sepa- 
rate it. And yet he does not identify it absolutely with the C. gobio, leaving for 
it a place apart in making the observation that “its snout is perhaps a little less 
pointed, and the spines above its nostrils a little larger,” without giving his opinion 
on the value of these differences. The size of the specimens which he has examined 
measured three inches, and if this be the common size, the species is smaller than 
the C. gobio of the Seine, and many others. 
There is, in this reserve of Cuvier, not to identify definitively two fishes of such 
distant countries, and nevertheless so similar to each other; there is, I say, included 
in this reserve, the whole spirit of modern science, a spirit profoundly philosophical, 
the spirit of future progress. 
We have deemed it necessary to make several generic divisions of the species 
hitherto comprised in the genus Cottus. This part of our labor was published in 
the Proceedings of the Boston Society of Natural History,' and we think it in place 
to transcribe here the historical paragraph which relates to that question, since it 
might be controverted by some one. 
Artedi established the genus Cottus in 1738 with the following characters: gill 
membrane containing six distinct bony rays; head larger than the body, depressed 
and acute. Two dorsal fins; the anterior composed of flexible spines. Ventral 
fins small, having only four soft rays. Skin scaleless.” 
He places in the first rank the fresh water species having two spines on the head, 
of which C. gobio is the type, being the only one known at that time. Next to 
this, the species with more spines on the head, including not only the salt water 
species having a smooth skin, but two others, which have since become, one the 
type of the genus Aspidophorus, the other the type of the genus Callionymus. 
Artedi himself went thus beyond the limits of his genus by placing in it the twu 
last species, as their body is covered with scales. 
Linneus’ alters Artedi’s genus by giving as the only character for it, “a spiny 
head broader than the body.” Linnzeus went farther; he transposes the species 
and places at the head C. cataphractus, the type of the genus Aspidophorus, of later 
date, and which Artedi placed at the end of the genus Cottus. His third species 
belongs now to the genus Batrachus, and the fourth to the genus Platycephalus: 
the C. gobio is the last. 
Oth. Fabricius' followed the example of Linnzus. 
But Cuvier’ recalls that the primitive type of the genus Cottus was C. gobio 
* Vol. iii., 1850, pp. 183, 303, and vol. iv., 1851, p. 18. 2 Genera Piscium. 
* Systema Nature, ed. xii. 4 Fauna Greenlandica, 1780, p. 159. 
* Histoire Naturelle des Poissons, iv., 1829, pp. 142, 150. 
