82 



CHALMER L. COOPER 



Sandstone, Massive to Irregular bedded, fine to 

 medium grained. 



Shale, black, laminated to flaky. 

 micaceous 



Sandstone, irregular bedded, fine 

 white to greenish-bro' 



Shale, calcareous, fossiliferous (upper 2-3' 

 _i silty, micaceous). 



Limestone, thin bedded, lenticular, fossi 



- 4 



Shale, gr<y, calcareous, fossiliferous 



Limestone, thin, irregularly bedded, fossi 



- 2 thin shale partings 



••-Shale, gray, poorly exposed. 



Limestone, gray, massive, fossiliferous 



Fig. 1 — Mississippian-Pennsylvanian contact in 

 Johnson County, Illinois. The arrows to the 

 right of the column show the approximate 

 position of samples collected for study. The 

 beds were sampled so that all zones from the 

 top of the massive limestone at the bottom 

 of the column to the base of the Lick Creek 

 sandstone were collected. 



shows that the two basins (Arkansas and Illinois) 

 were connected and that favorable ecologic con- 

 ditions of unknown duration enabled faunal mi- 

 gration of some distinctive organisms. 



All zones in the Kinkaid shales above the 

 massive limestone shown at the base of the 

 column in figure 1 contain a microfauna in 

 varying amounts, principally ostracodes. 

 However, the samples above and below the 

 upper thin irregularly bedded limestone 

 proved to be the most fruitful, zone 5 

 furnishing the fusulines which are described 

 later. The Wayside shales above the 

 Kinkaid are barren of fossils. 



A short time ago the very primitive, short 

 axis fusuline, Millerella, was described by 

 Thompson (1942, p. 404). The holotype 

 came from the type locality of the Marble 

 Falls formation in Burnet County, Texas, 

 and the paratypes were collected from the 

 "Bend" series in the Hueco Mountains of 



Explanation of Plate 19 



Figs. 1-5 — Millerella Chester ensis Cooper, n. sp. 1, 4, Saggital sections with endothyroid juvenaria* 

 and irregular coiling as shown by the elongate volution and lack of continuity of the tunnel 

 in the plane of the section, X100. 2, 3, Axial sections, showing modified hour-glass outline, 

 X100. 5, Enlargement of 1 to show details of coiling of first volution in a plane at right 

 angles to the plane of the section, X200. Kinkaid forma'tion, bed 5, Johnson County, Illi- 

 nois, (p. 85) 

 6-8 — Millerella zelleri Cooper, n. sp. 6, 8, Sagittal sections showing uniformity of coiling and 

 tunnel, the latter lying almost wholly in the plane of the section, X100. 7, Axial section, 

 X100. Kinkaid formation, bed 5, Johnson County, Illinois. (p. 86) 



9, 11 — Millerella kinkaidensis Cooper, n. sp. Sagittal and axial sections, the latter showing the 



relatively long axis and modified keel-like margin, X 100. Kinkaid formation, bed 5, Johnson 

 County, Illinois. (p. 86) 



10, 12 — Millerella sp. External views of two specimens, X60. (p. 83) 

 13 — Millerella cf. M. pinguis Thompson. Sagittal section, X100. Dornick Hills group, sec. 12, 



T. 3 S., R. 2 E., Carter County, Oklahoma. # (p. 83) 



14-15 — Millerella marblensis Thompson. Sagittal and axial sections, X100. Same horizon and 



locality as fig. 13. (p. 83) 



16-17 — Millerella advena Thompson. Sagittal and axial sections, the latter showing inflated 



character and eccentric coiling of early volution, X 100. Lower Dornick Hills group, NW. \, 



NW. i NE. i, sec. 16, T. 6 S., R. 2 E., Carter County, Oklahoma. _ (p. 83) 



18 — Millerella inflecta Thompson. Sagittal section from the Belden formation, bed 15, section 



P-15, Sweetwater Creek. Near Glenwood Springs, Colorado, X100. (Thompson, 1945, 



p. 44, pi. l,fig. 5.) (p. 83) 



