CHALMER L. COOPER 



Family Endothyridae Rhumbler, 1895 

 Genus Endothyra Phillips, 1845 



A great variety of species has been as- 

 signed to this genus by various workers in 

 this country and abroad, forms ranging 

 from the almost completely evolute E. gal- 

 lowayi Thomas, discoid forms such as E. 

 ammonoides Brady and E. subtilissima 

 Brady, to such involute species as E. globula 

 (d'Eichwald). Many intermediate forms 

 with varying degrees of involution exist, 

 such as E. ameradaensis Harlton and E. 

 media Waters. Others, partially evolute on 

 one side and involute on the other include 

 the well-known E. baileyi (Hall) and the 

 genotype species, E. bowmani Phillips. The 

 habit of coiling is also extremely variable, 

 as shown by the regular planispiral of the 

 very flat species to the very great excentric- 

 ity of thick, bulbous forms exemplified by 

 E. baileyi. However, the heterogeneity of the 

 latter species is not so marked as was first 

 supposed, as shown by Scott, Zeller and 

 Nodine (1946), who demonstrate that it has 

 a definite axis of coiling for each half volu- 

 tion. Several species now classified with 

 Endothyra probably should be listed with 

 the primitive fusuline Millerella Thompson 

 (1942), such as E. radiata Brady, E. globula 

 (d'Eichwald) (Harlton, 1927) and possibly 

 E. ornata Brady to judge from its sagittal 

 section. 



Endothyra acuta Cooper, n. sp. 

 Plate 20, figures 24, 30 



Shell medium sized, 8 chambers in last 

 volution; periphery rounded; chambers 

 large and somewhat arched at periphery 

 due to deeply incised sutures as seen in 

 lateral outline; septal angle somewhat less 

 than normal, giving ~a "backward swing" 

 appearance, especially in last three or four 

 chambers; slightly biumbilicate, the left side 

 being more evolute; apertural face abrupt, 

 not in a plane normal to axis of coiling be- 

 cause the right side of the arch around the 

 aperture has developed faster than the left, 

 making it possible to view aperture from the 

 left side. 



Greatest diameter (holotype), ca. 0.56 

 mm.; diameter, last chamber, ca. 0.20 mm.; 

 axial thickness, ca. 0.19 mm. (These dimen- 

 sions are approximate as last chamber of 

 holotype is crushed.) 



E. acuta resembles E. whitesidei Galloway 

 and Ryniker in shape of chambers, but lacks 

 the marked evolute character of the latter. 

 It also has a larger aperture and conse- 

 quently a higher apertural face than the 

 Pennsylvanian species. 



Kinkaid formation, beds 4 and 5, Johnson 

 County, Illinois. 



Endothyra excentralis Cooper, n. sp. 

 Plate 20, figures 19-23 



Shell small, thick, 6 to 8 chambers in last 

 volution; periphery rounded; chambers 

 bulbous, especially the final one which is 

 much thicker proportionally than the 

 others; sutures distinct and incised; right 

 side completely involute, left somewhat 

 umbilicate; aperture a crescent-shaped slit 

 located at the base of chamber, extending 

 from the center down the umbilicate side. 



Greatest diameter (holotype), 0.48 mm.; 

 diameter last chamber, 0.26 mm.; axial 

 thickness, 0.16 mm. 



E. excentra is similar to E. media Waters, 

 E. ovata Waters, E. distenta H. J. Plummer, 

 and E. rothrocki Harlton, but the shape of 

 the aperture differentiates it from the first 

 three and the central position of the aperture 

 distinguishes the latter. 



Kinkaid formation, beds 4 and 5, Johnson 

 County, Illinois. 



Family Astrorhizidae Brady, 1881 



Genus Hyperammina Brady, 1878 



Hyperammina cf. H. elongata 



CLAVATULA HOWCHIN 



Plate 20, figures 25-27 



Hyperammina elongata clavatula Howchin, 1888, 

 Royal Micr. Soc. Jour., p. 535, pi. 8, figs. 1,2; 

 Mississippian limestones of England. — Harl- 

 ton, 1927, Jour. Paleontology, vol. 1, p. 16, pi. 

 1, figs, la, b; Upper Caney shale, Oklahoma. — 

 Harlton, 1933, idem, vol. 7, p. 8, pi. 1, figs, la- 

 e; John Valley shale, Okla. 



The Kinkaid specimens cannot be dis- 

 tinguished from those occurring above 

 and below the Mississippian-Pennsylvanian 

 boundary in Oklahoma. However, . they 

 lack the pointed proloculum of //. elegantis- 

 sima H. J. Plummer, and H. spinescens 

 Cushman and Waters and the globular 

 proloculum of 77. bulbosa Cushman and 

 Waters, reported by Mrs. H. J. Plummer 

 from younger beds in Texas. 



