PRELIMINARY NOTICE 
OF NEW GENERA AND SPECIES OF FOSSILS, BY C. A, 'WHITE, M. D., AND 
O. H. ST. JOHN. 
The fossils here briefly described possess such unusual interest that it is thought 
desirable to announce them, in this manner in advance of their more complete description 
and illustration in the proceedings of the Chicago Academy of Sciences, accompanied with 
many others, which cannot take place under a number of months. 
PROTOZOA. 
In the sedimentary material of the U. coal-measures of Pottawattamie county, we have 
found numerous specimens of a discoid body, which seems to us to be a species of 
Amphlsteglna; the first of that genus, we believe yet discoveredin strata more ancient than 
the Tertiary. It is yet under investigati on. 
MOLLUSC A. 
Aulosteges Spondyliformis, (n. s.) Shell minute, parasitic, subtriangular in outline. 
Ventral valve attached to foreign objects by its spines, which are numerous and rather long 
From the upper coal-measures of Appanoose and Pottawattamie counties. 
Many of the characters of the following described shell are similar to those of Waldheimia 
but the crura of the loop are joined together, at least in some cases, and the loop-band is 
armed with numerous spines, which point outward in all directions. These and other 
characters are now under investigation. Should they confirm our present belief of their 
generic value, we propose for the shell the generic name of Oryptacanthia , meanwhile we 
refer it with doubt to Waldheimia. 
Waldheimia Compacta , (n. s .) Shell small, compact, smooth, finely punctate; back 
view subtriangular, dorsal view subpentangular. Depth of ventral valve from lateral 
margin to bottom, nearly equal to the greatest width of the shell. This shell is associated 
with the Terebralula millipunctata of Hall, which however has the true lo op of Waldheimia. 
From the upper coal-measures of Madison county. 
Beyrlchia lithofactor (n. s.) Valves subovate or oblong in outline, smooth or finely 
granular; dorsal margin gently curved, anterior and posterior margins strongly rounded; 
ventral margin straight, and about three-fourths the length of the shell. Sides divided into 
two somewhat prominent lobes by a deep depression, which extends rather more than half 
way to the dorsum. The posterior lobe is most prominent, and has a slight vertical depres¬ 
sion near its middle, running up to the dorsal margin. The front lobe is marked by a 
, DSS 
