Three Great Fossil Placoderms of <>hi<>. — Claypole. 93 
One of these Titanichthys is the largest placoderni known 
from Ohio and probably from the continent. Most of them 
were found originally by Mr. Terrell, though other and better 
specimens have since rewarded the labors of later palaeontol- 
ogists. Unfortunately most of his specimens, including all 
the finest, were destroyed in the great fire at Elyria and had 
he not had the foresight to make and distribute photographs 
of them we should have no monument of his labor-. 
This great fish-fauna brought to light about 1870 was fol- 
lowed in a few years by the discovery of a third locality. In 
the valley of the Cuyahoga and of Rocky river Dr. W. (lark. 
of Berea, found, about the year 1SS5, the first of a series 
which proved only the earnest of a truly magnificent collec- 
tion. While many of his specimens were, as might have been 
anticipated, identical with those of Mr. Terrell, yet not a few 
are new and greatly enlarge our ideas of the fauna of the 
Cleveland Shale. 
The monarch of these muddy shores — the gigantic Titan- 
ichthys — of whose remains detached plates have been found 
at Avon Point, is only known in size and detail (thus far) by 
the more nearly complete specimens exhumed from the valley 
of Roek3 T river. His rival, more formidably armed and armour- 
clad, though of rather smaller size — Dinichthys — is also now 
better understood in consequence of Dr. Clark's discoveries. 
Still another species, the contemporaries of these, though not 
placoderms, and therefore outside of our present field, yet 
await examination and study.* 
Several other laborers have worked in the same field, such 
as Kepler, Could. Wagner. Park. Terrell and Wheat, and suc- 
cess has, in a greater or less dew-pee. attended all their efforts. 
But to the three above named and Dr. .1. 8. Newberry, who has 
skillfully interpreted the t'os-ils. is the world especially in- 
debted for it- present knowledge of the ancient fish-fauna of 
central < )hio. 
The future has vastly more in store than the pasl has re- 
vealed. "The harvest is plenteous but the laborers are few." 
Time and patience, such as these men have shown, are rare. 
♦Note. — Since this passage was written some of these have been de- 
scribed by the writer. See "The Cladodont Sharks of the Cleveland 
Shale,'' in the May number of this Magazine. 
