MICROFAUNA FROM JOHNSON COUNTY, ILLINOIS 



87 



chesterensis by its thicker spirotheca, shorter 

 and thicker septae, its regularity of coiling, 

 and shorter axis. This is one of the smallest 

 described species of Millerella. 



Kinkaid formation, bed 5, Johnson 

 County, Illinois. 



Family Ammodiscidae Rhumbler, 1895 



Genus Glomospira Rzehak, 1888 



Glomospira disca Cooper, n. sp. 



Plate 20, figure 18 



Test minute, free, early volutions ir- 

 regularly coiled, but tending to lie within 



Genus Trepeilopsis Cushman and Waters, 



1928 



Trepeilopsis mississippiana Cooper, n. sp. 



Plate 20, figures 34-41 



Test attached to Productus spines or free, 

 coiled in a tight conical spiral in early volu- 

 tions, later becoming a cylindrical coil, 

 finally the tube bends down across the spiral 

 coils in a broadly curved manner that is 

 roughly S-shaped; aperture at end of tube, 

 wide, somewhat flared. 



Length (holotype), 0.52 mm.; diameter of 

 tube in last whorl, 0.05 mm.; width of 

 aperture, 0.056 mm. 



Table 3.- 



-Statistical Data for M . zelleri, Measurements 

 in Microns 



Spec. 3 



Septal count 



Diam. 

 Proloc. 



L. 



W. 



Ratio 



Ht. volutions 



Tunnel 



1 



2 



3 



4 



1 



2 



3 



4 



5 



angle 



1 

 2 

 3 



11 

 9 



14 

 11 



16 



13 



18 

 16 



20 

 20 



23 



10 



27 



1:0.36 



13 

 13 

 13 



20 



27 

 20 



27 

 33 

 33 



40 

 40 

 40 



46 



53 

 46 



Ca. 10° 



3 Specimens 1 and 2 are sagittal sections, and 3 are axial section. Specimen 1 is shown on pi. 19, fig. 

 2, fig. 6, and 3, fig. 7. 



plane of the last coil; tube increases regularly 

 in diameter. 



Diameter, 0.23 mm.; thickness, 0.12 mm. 



G. disca is smaller and more regularly 

 coiled than G. siluriana Ireland, nor is the 

 coiling so irregularly developed as in G. 

 diver sa Cushman and Waters. 



Kinkaid formation, beds 5, 6, Johnson 

 County, Illinois. 



T. mississippiana differs from S. grandis 

 Cushman and Waters by the marked curva- 

 ture of the latter portion of the tube and 

 from T. spirans (Cushman and Waters) by 

 the flaring aperture. It can be separated 

 from an undescribed Kinderhook species by 

 the smaller size, tighter coiling, and the long 

 taper of the latter. 



Explanation of Plate 22 



Figs. / — Kirkbyella quadrata Croneis and Gutke. Lateral view, X50. 



2-4 — Healdia sulcata Cooper n. sp. Dorsal, lateral and end views of holotype, X50. 



5-7 — Healdia caneyensis Harlton. Dorsal, lateral and end views, X50. 



8-10 — Healdia aequabilis Cooper. Dorsal, lateral and end views, X40. 



11-13 — Healdia elliptica Cooper. Dorsal, lateral and end views, X50. 



14-16 — Healdia tenuicosta Cooper. Dorsal, lateral and end views, X50. 



17-19 — Cavellina ovatiformis (Ulrich). Dorsal, lateral and end views, X30. 



20-23 — Hollinella radiata (Jones and Kirkby). Dorsal, lateral, ventral and end views, 



24-26 — Glyptopleura circumcostata Cooper. Dorsal, lateral, and end views, X40. 



27-29 — Glyptopleura varians Croneis and Funkhouser, X40. 32, 34, Dorsal and end views. 



33, Lateral view of left valve of another specimen. 

 30-31 — Cavellina librata Cooper. Dorsal and lateral views, X40. 

 32-34 — Glyptopleura similis Croneis and Funkhouser. Dorsal lateral and end views, X40. 



(p. 90) 

 35 — Glyptopleurina iniqua Cooper. Lateral view of broken valve, X40. (p. 85) 



(p. 90) 

 (p. 83) 

 (P- 83) 

 (p. 83) 

 (p. 85) 



X30. 

 (p. 85) 



