16 
IOWA ACADEMY OF SCIENCES. 
the great field of science itself the results may seem small; measured by 
the standard of individual achievement the outcome is stupendous. In 
the special department of knowledge which he represented no one person 
has done more to raise it to the high place that it now occupies. 
Wachsmuth belonged to that illustrious school of naturalists which 
Louis Agassiz founded in this country. His main efforts were entirely 
along the lines of inquiry pointed out by the Swiss savant. It was the 
establishment, upon a morphological basis, of a rational classification of a 
group of organisms. The group chosen was the crinoids, or sea lilies, a class 
of animals which is now all but extinct, but which in ages past was one of 
the most abundant forms of life. Most of the material was fossil and the 
difficulties surrounding the investigation were such as to students of living 
animals would be insurmountable. Although the work was far from fin- 
ished at the time of his demise the main and most important features of the 
scheme were fully established and the Wachsmuth classification of crinoids 
has been adopted the world over. 
In the Monograph of the Fossil Crinoids, which is a huge quarto of 800 
pages in two parts and an atlas of eighty plates, is contained the mature 
reflections of thirty years’ continuous thought and reflection. Twenty years 
ago, when at Cambridge with Agassiz, the foundations of his life’s work 
were laid, In a little paper “ On the Internal and External Structures of 
Paleozoic Crinoids,” published in 1877, was stated the essential proposi- 
tions on which rested all subsequent work. The ancient crinoids were 
divided into three primary groups, the separation being based chiefly upon 
the structure of the tegmen. 
The effects of Wachsmuth’s work has been completely to revolutionize 
the ideas which prevailed concerning the crinoids and to place the whole 
systematic arrangement of the groups upon an enduring basis. The stages 
in the development of those changes are easily traced in the various publi- 
cations which were issued from time to time and culminated in the monu- 
mental monograph. 
THE STATE QUARRY LIMESTONE. 
BY SAMUEL CALVIN. 
At the state qaarries, or North Bend quarries, in sections 
5 and 8 of Penn township, Johnson county, Iowa, there is a 
body of limestone of Devonian age, possessing marked char- 
acteristics which set it off sharply from the rest of the Devo- 
nian in the upper Mississippi valley. The formation has a 
thickness of about forty feet. At present there is some uncer- 
tainty as to its exact taxonomic relations. 
On fresh fracture the state quarry rock is light gray in 
color. In texture it varies somewhat in different beds, but 
