216 I'he American Geologist. April, 1895 
along the sides of the hill hiive leached out some of the color- 
ing matter of the black clays and have thus produced the ap- 
pearance that the hills now present, viz. : a black nucleus 
mantled by gray clays. It has been suggested to me, to call 
the black cla3^s an nnireiifhered nucleus. In some cases the 
dift'erence between the gray and blackish clays may be due to 
different lithologic constitution, but I have never seen any ev- 
idence of an erosion period intervening between the '"Arcad- 
ia clays" and the Lower Claiborne beds. 
On only one of the Iiilltops above the "Arcadia clays" did 
I find fossils and that was on the La. & N. W. railway, between 
five and six miles south of Gibbsland. Here gray and mottled 
clays grade upward into red claj's which contained a cast of 
Venericardia planicosta : as this species is found in both the 
Jackson and lower P^ocene beds, it does not fix the age of 
these beds. But on Hammett's branch, S. W. ^, Sec. 30, Twp. 
18 N., R. 6 W., in a gray joint clay numerous Lower Claiborne 
fossils, such as Anomia ephiiypoidcs and /''label/ ton eiinet'forme 
var. pac/ii/p/n/lluni, were found. On p. 11 of his first report. 
Dr. Lerch states: "A paucity of fossils characterizes these de- 
posits, and so far only near the line of contact with the un- 
derlying green sand, marine shells have been found which 
prove to be the same as those found in the underlying Clai- 
borne formation." 
I believe that the name -'Arcadia clays" must be abandoned 
and the cla^^s for which the name stands be referred to the 
Lower Claiborne. 
The Small Prairies of Wi)rii <nid JValcJN'loches Parishes * 
Unfortunately, from lithologic and topographic resemblance, 
much of the Lower Claiborne of Louisiana has been confused 
with the Jackson. Johnson states on p. 16 of his report on 
the "Iron Regions of Louisiana and Texas" : "The boundary 
of this formation [the Jackson] was traced by prairies and 
wells along the left bank of Bayou Saline and from the S. W. 
^ of Sec. 20, T. 16 N.. R. 5 W.. northeastward to Gansville, 
near the borders of Jackson and Winn parishes, and runs di- 
agonally through Jackson parish in the direction of Monroe, 
*irntil the author had studied the fossils foinid in 1 in^se prjiiries, he 
tlioiiuiit some of the Lower Claiborne was .lackson. 
