v 
A871.) v0 [Cope. 
This species may have more affinities with Ama than with the Chara- 
cinide. A single specimen was obtained ina clay nodule by the naturalists 
of the U. S. Paraguay Expedition under Capt. Page, from the neighbor- 
hood of Para. It was accomvanied by several specimeus of a fish from 
other nodules, which closely resembles an Aspidorhynchus. Museum of 
the Smithsonian Institution. 
On the occurrence of fossil Cobitidw in Idaho. 
By E. D. Coreg. 
(Read before the American Philosophical Society, March 3, 1871.) 
Of the five genera of extinct Cyprinide and allied forms discovered by 
Capt. Clarence King*in the fresh water deposit of Catharine’s Creek, 
etc., Idaho, the writer has been able to indicate the affinities of three. 
Thus Semotilus, Anchybopsis and Mylocyprinus, were regarded as repre- 
sentations of existing types of both carnivorous and herbivorous labits. 
Oligobelus and Diastichus were not assigned to any definite position in 
relation to known types of the same great group, and I am still compelled 
to leave the former in the same uncertain position. Diustichus I find, on 
the other hand, presents the peculiar direction of the pharyngeal teeth 
which is characteristic of the Cobitide, and I suspect that it-represents a 
form of that family. I am entirely confirmed in this conclusion by the 
discovery, amoug the specimens submitted to me by the Smithonian 
Institution, of the inferior element of the three modified anterior vertebriv, 
which are so characteristic of certain families of the Physostomous fishes. 
” This portion, moreover, is that which occupies this position among the 
Cobitide only among them. It consists of a longitudinal plate terminat- 
ing posteriorly in a bladder-like chamber on each side, each of which is 
closed below by a transverse process of the inferior plate : an angular 
fissure extends round the ends of these, and at the angle sends a short 
continuation upwards. This is quite similar to what is observed in 
Cobitis. The specimen described is apparently adult, and indicates a con- 
siderably smaller species than either the Diastichus macrodon or D. 
purvidens. : 
The occurrence of Cobitide is perhaps the most interesting fact brought 
to light by the examination: of these extinct fishes. ‘All of the numerous 
existing species are found in the Eastern Hemisphere, and the great 
majority in tropical Asia, a few only occurring in Europe and South 
Africa. Extinct species are found in the Miocene of Oeningen. We have, 
then, in the genus Diustichus another example of the occurrence of Asiatic 
types in North America prior to the glacial epoch, and as in a freshwater 
fish, strongly suggestive of continuity of territory of the two continents. 
* See Proczed. Amer. Philos. Soc., 1570, 539. 
