86 



CHALMER L. COOPER 



Table 1 



-Statistical Data for M. chesterensis, Measurements 

 in Microns 



Spec. 1 



Septal Count 



Prol. 

 Diam. 



L. 



W. 



Ratio 



Ht. Volutions 



Tunnel 



1 



2 



3 



4 



5 



1 



2 



3 4 



5 



Angle 



1 







11 



14 



18 



114 



20 



— 



— 



— 



13 



20 



27 



40 



— 





2 



— 



9 



13 



15 



17 



20 



— 



— 



— 



— 



20 



27 



40 



53 





3 













20 



160 



430 



1:0.37 



13 



40 



53 



60 



61 



21° 



4 













20 



140 



350 



1:0.40 



13 



20 



27 



40 



60 



21° 



1 Specimens 1 and 2 are sagittal sections, 3 and 4 are axial sections. Specimen 1 is illustrated in pi. 19, 

 figs. 1, 5; 2, fig. 4; 3, fig. 4; and 4, fig. 2. 



Millerella kinkaidensis Cooper, n. sp. 

 Plate 19, figures 9, 11 



Shell small, discoidal; periphery sub- 

 rounded, involute, and only slightly umbili- 

 cate; walls thick, septa short, thick and 

 slightly curved; chambers small and about 



Kinkaid formation, bed 5, Johnson 

 County, Illinois. 



Millerella zelleri Cooper, n. sp. 

 Plate 19, figures 6-8 



Shell very minute, regularly coiled, septa 



as wide as high (see sagittal section); prolo- very short, thick, tapered, closely spaced, 



Table 2. — Statistical Data for M. kinkaidensis, Measurements 

 in Microns 



Spec. 2 



Septal count 



Diam. 

 Proloc. 



L. 



W. 



Ratio 



Ht. volutions 



Tunnel 



1 



2 



3 



4 



1 



2 



3 



4 



5 



angle 



1 

 2 



8 



13 



16 



20 



26 



23 



18 



36 



1:0.50 



13 



20 

 20 



27 

 33 



46 

 46 



46 



74 



±30° 



2 Specimen 1 is a sagittal section, 2 an axial section. Specimen 1 is shown on pi. 19, fig. 9; 2, fig. 1 1 



culum relatively large; juvenarium endo- 

 thyroid. Data on shell measurements and 

 septal counts is shown in table 2. 



M. kinkaidensis has a longer axis and 

 larger proloculum than the other two 

 Kinkaid species of Millerella. It differs from 

 Pennsylvanian species much as the other 

 Kinkaid species do. 



forming rather small chambers; periphery 

 rounded; axial regions slightly and nearly 

 equally umbilicate, completely involute; 

 juvenarium endothyroid, but nevertheless 

 the coiling is regular. 



Data on shell measurements and septal 

 counts is shown in table 3. 



M. zelleri is distinguished from M. 



Explanation of Plate 21 



Figs 1-3 — Balantoides reticulatus Croneis and Thurman. Dorsal, lateral and end views, X50. 



(p. 84) 

 4-6 — Cornigella tuberculospinosa (Jones and Kirkby). Dorsal, lateral and end views 



X50. 

 (p. 89) 

 (p. 90) 



(p. 84) 

 (p. 84) 

 (p. 90) 

 (p. 89) 



7-8 — Cornigella golcondensis (Croneis and Gale). Dorsal and lateral views, X50. 

 9-12 — Ectodemites planus Cooper. Dorsal, ventral, lateral and end views, X40. 

 13 — Beyrichiopsis thori Coryell and Johnson. Lateral view, X40. 

 14-16 — Ectodemites tumidus Cooper. Dorsal, lateral and end views, X40. 

 17-18 — Coryellites concava (Cooper). Dorsal and lateral views, X40. 



19-22 — Amphissites insignis Croneis and Thurman. Dorsal, ventral, lateral, and end views of 

 two specimens (fig. 19, is a single valve), X30. (p. 84) 



23-24 — Coryellites portica Cooper, n. sp. Dorsal and lateral views, X40. (p. 89) 



25-26 — Bairdia golcondensis Croneis and Gale. Dorsal and lateral views, X40, (p. 84) 



27-28 — Bairdia attenuata Girty. Dorsal and lateral views, X40. (p. 84) 



29-30 — Bairdia impendere Cooper. Dorsal and lateral views, X40. (p. 84) 



