no. 8 SMITHSONIAN EXPLORATIONS, 1913 15 
The investigations of the past summer were confined to the Kas- 
kaskia rocks of Monroe and Randolph Counties, [linois. They were 
systematically carried on in connection with the geological work 
for the State of Illinois, in progress at the same time under the direc- 
tion of Professor Weller, in order to have the benefit of accurate 
determinations of the horizons from which the collections were made, 
with reference to the several subordinate formations into which the 
Fic. 17.—Portion of a slab of fossil Crinoids from Illinois. 
7 _I0 
Photograph by National Museum. 
Kaskaskia of that region 1s divided. In this way it was hoped to 
rectify some confusion as to the stratigraphic relation of a number 
of species described in the Geological Reports of [linois and Iowa. 
The operations were successful in this respect, and at the same time 
six large boxes of fine specimens were obtained. Among the speci- 
mens there are a number of slabs covered with Crinoids not hitherto 
found in that formation, in an excellent state of preservation. A por- 
tion of one slab, containing 22 specimens of 9 different species, is 
shown in the accompanying illustration (fig. 17). This specimen and 
