40 Os Lit LIAS HATLAIIN, 
toward the posterior angle; the two posterior rows often rudi- 
mentary. Some of the tubercles, when worn by use, become 
elongated in the direction of the rows to which they belong, and 
others in an oblique direction. This species is readily distin- 
guished from all others previously described by the relative 
coarseness of its tuberculation. It is represented by a number 
of examples from the State Quarry beds of Johnson county, 
Iowa. 
NOTICE OF PROBLEMATICAL ORGANISMS 
Some thirty years ago Mr. Orestes St. John, when assistant 
in the Museum of Comparative Zodlogy, collected a number of 
Selachian teeth and spines and some large Dinichthyid plates 
from a ‘‘fish-bed”’ near Burlington, lowa, supposed to be near 
the dividing line between Upper Devonian and typical Kinder- 
hook. Small spines of Stethacanthus, Erismacanthus, and Homa- 
canthus are rather abundant at this locality, also dermal tubercles 
of sharks. From the upper part of the formation Mr. St. John 
obtained the carapace of a Schizopod crustacean, and also some 
vegetable remains, such as branches of a Lepidodendron and 
woody fibers. In addition he found a number of peculiar fossils 
of which the one shown in Fig. 2 is a fair example, and within 
the past year other specimens of the same sort have been col- 
lected by Professor Udden in the Kinderhook near Burlington. 
An examination of the latter forms by Professor Arthur 
Hollick of Columbia College leads him to the opinion that they 
are cone-scales of some conifer probably allied to Avaucaria. 
A figure is given herewith for the benefit of those interested in 
the study of Mississippian faunas. 
EXPLANATION OF VEIGUIRISS 
Fic. 1. Dinichthys pustulosus E. Hamilton limestone; Milwaukee, Wis- 
consin. Left ramus of mandible. x 2. 
Fic. 2. Cladodus monroei sp. nov. Hamilton limestone; Milwaukee, 
Wisconsin. 2. é 
FIG. 3. Supposed cone-scale from Kinderhook fish-bed at Burlington, 
Iowa. X =. 
