780 1HE JOURNAL OF GEOLOGY. 
While in the yellowish shales—No. 19—between the flint 
and concretionary limestone are: 
1. Athyris (Seminula) subtilita, (Hall) Newb. = A. argentea, 
(Shiep,)) Keyes (@) 
2. Productus semireticulatus, (Martin) de Koninck. (r) 
3. Derbya multistriata, (M. and H..) Pros. (?) (rr) 
4. Derbya crassa, (M. and H.) H. and C. () 
5. Septopora biserials, (Swallow) Waagen. (r) 
6. Myalina recurvirostris, M. and W. (tr) 
7. Archeocidaris, sp. (Cc) | 
8. Aviculopecten, sp. (fr) 
9. (?) Edmondia. sp. (rr) 
10. Crinoid stems." 
Finally, in the massive concretionary layers, and in the con- 
cretions themselves, are fossils among which Brachiopods are the 
most numerous and characteristic. The following species were 
obtained in Marion county : 
1. Athyris (Seminula) subtilta, (Hall) Newb. = A. argentea 
(Sngo,)) Neves. (we) 
2. Aviculopecten occidentalis, (Shum.) M. and W. (?) (rr) 
Edmondia, sp. (tr) 
Productus senureticulatus, (Martin) de Koninck. (rr) 
Derbya multistriata, (M. and H.) Prosser. (r) 
Septopora biserialis, (Swallow) Waagen. (r) a 
Archeocidaris, sp. (Cc) 
Crinoid segments. 
Paleontologically the Marion concretionary limestone is an 
important stratigraphic horizon for in the higher fossiliferous 
rocks Brachiopods are seen at rare intervals and rapidly dis- 
appear. The fauna of the succeeding rocks consists almost 
entirely of Lamellibranchia and is composed of species which are 
oO ae 
tProfessor Broadhead stated that at Marion, ‘‘Awzculopecten occidentahs and 
Fusulina cylindrica were the only fossils seen” (Trans. St. Louis Acad. Science, Vol. 
IV., Pt. I1]., p. 492). I have not yet seen Ausucna as high as the Marion horizon and 
Meek and Hayden did not find them above a thin limestone which they reported as 
thirty-five feet above the horizon of the Cottonwood limestone (Proc. Acad. Nat. Sci. 
Phil., Vol. XI., p. 17, No. 22), which would locate it in the lower part of the Neosho 
formation. 
