DIPTERUS IN THE AMERICAN MIDDLE DEVONIAN 495 
fauna comes in above the ledges from which Owen collected 
fossils that he referred to the Chemung (‘ Spirifer euruteines,”’ 
CEG); 
Lately I have found another somewhat more strongly tuber- 
culated tooth of Dipterus, (see Fig. 1) near Buffalo, lowa, at a level 
about 25 feet lower down in the same limestone. The ledge from 
which this tooth came, contains S¢trzatopora rugosa and Megisto- 
crinus latus. It is directly under the ledges in which Spirifer 
parryanus first appears. It has yielded teeth of Ptychtodus and 
fragments of Dinichthys pustulosus. Some coral-bearing ledges, 
full of fossils, he four or five feet above it.* The ledge belongs 
to the Hamilton as described by Worthen in Rock Island county, 
Illinois, on the opposite side of the Mississippi, and comes in 
some fifteen or twenty feet above its base. 
While this fish is reported from the Lower Devonian in 
Europe and Great Britain, it has not before this, I believe, been 
observed as low down as the Middle Devonian in America, to 
which age American geologists have referred the fauna of this 
limestone. . 
J. A. UDDEN. 
2Megistocrinus bed. Iowa Geol. Surv., Vol. LX, Pl. VI. 
