THE 
AMERICAN GEOLOGIST 
Vol. X. NOVEMBER, 1892. No. T) 
NEW LOWER SILURIAN OSTRACODA, NO. 1. 
By E. O. Ulrich, Newport, Ky. 
Plate IX. 
This is tlie first of a series of papers upon these fossils that T 
hope to issue in the near future. Each part will be accompanied 
by at least one plate, and the rate of publication will depend very 
largely upon the leisure time at my disposal. 
My aim is to advance the subject to a point where it will be pos- 
sible to treat it monographically. The first essential for that 
condition is, obviously, a knowledge as complete as possible of 
the forms to be worked upon and classified. I propose, therefore, 
to publish descriptions and figures of all the new forms now in 
mj' hands, with occasional notes upon pi'cviously known species. 
I may add that these papers are to be regarded as in a great 
measure preliminary. Many of the species, all of those occurring 
in the Nortwestern states, will be reworked, I trust, more fully, 
and republished in Vol. iii of the final reports of the Geological 
and Natural Histor}' Survey of Minnesota. 
The systematic classification of these, mostly minute, paleozoic 
fossils, is attended with unusual difificulties. This fact must be- 
come apparent to anyone taking the troulde to enter into critical 
comparisons between the British, German and American works on 
the subject. It is not that a particular style of treatment pertains 
to each of these nations. No, no. It is, rather, that the num- 
ber of styles is limited only by the number of authors. The 
