ROTIPHYLLUM 



33 



cardinal side fused with each alar; right 

 alar combination free; holotype 15 mm long 

 on convex side, calyx 12 mm in diameter. 



Paratype strongly curved, abruptly flar- 

 ing, about 6 mm long on convex side, 8 mm 

 in diameter at calyx; septa 24, with one 

 short cardinal followed in counterclockwise 

 direction by 2 fused, 1 free, 4 fused, 1 nearly 

 free, 5 fused, 1 free (counter), 3 fused, 1 

 nearly free, 3 fused, and 2 free major septa; 

 minor septa alternate with majors. 



Another paratype (diameters 5.9 by 6.7 

 mm) has 18 septa, cardinal septum in fos- 

 sula on convex side, followed on either side 

 by groups of 4 septa (last of which is almost 

 free alar septum) ; counter septum bordered 

 by groups of 4 septa. 



Transverse section. — One to three tab- 

 ular intersections between septa in late 

 ephebic stage. In late neanic stage of holo- 

 type (diameter 2.4 mm) cardinal septum is 

 slightly longer than others, none reaches 

 center, and most are short and paired near 

 epitheca. 



Longitudinal section. — Tabulae about 

 normal to counter side, tilted proximally 

 somewhat toward cardinal side, flat or con- 

 cave; axial region composed of tabulae and 

 axial ends of septa, all reinforced with scler- 

 enchyme forming a flat-topped axial struc- 

 ture. 



Occurrence. — Localities 1, 2. 



Material. — Specimens studied, 36. Holo- 

 type, University of Cincinnati No. 3359; 

 figured paratypes. University of Cincinnati 

 No. 3359a; studied paratypes. University of 

 Cincinnati No. 24307 ; unidentified orig- 

 inal cotypes, University of Cincinnati No. 

 24308. 



Remarks. — This species was differentiated 

 from among the cotypes and is represented 

 by Miller's figured specimen, here desig- 

 nated the holotype, plus 14 paratypes. 



RoTiPHYLLUM HiANS Easton, n. sp. 

 Plate 3, figures 4-6; Plate 16, figures 6-8 



Zaphrentis caly cuius Miller, 1891 [in part], In- 

 diana Dept. Geol. Nat. Res., 17th Ann. Rept., 

 p. 10. Adv. sheets. 



Zaphrentis calyculus, Miller, 1892 [in part], In- 

 diana Dept. Geol. Nat. Res., 17th Ann. Rept., 

 p. 620. 



Externals. — Small, trochoid, somewhat 

 flattened; calyx oblique toward concave 

 side, shallow, with prominent oval axial boss 



parallel with or oblique to cardinal-counter 

 plane; epitheca thick, with rugae; calicular 

 budding observed; holotype 14 mm long 

 (convex side), 7 mm long (concave side), 

 calyx 10.7 by 9.7 mm in diameter. 



Calyx of holotype with 24 major septa, 

 arranged as follows in counter-clockwise di- 

 rection : cardinal septum prominently con- 

 nected to axial boss, 1 short free major, 4 

 fused, 1 single (right alar) , 3 fused, 2 fused, 



2 fused, 1 single, 4 fused, 1 single (left 

 alar), 3 fused, 1 single; minor septa re- 

 stricted to right (convex) side. 



Another specimen (diameters 11 by 9.7 

 mm), possesses 27 (possibly 28) majors ar- 

 ranged as follows (counterclockwise) : car- 

 dinal septum not prominent, in pronounced 

 fosuUa, leaning to right of cardinal-counter 

 plane, 3 fused, 2 fused and then fused to 

 third, 1 free and short, 1 free and short 

 (right alar), 11 single extending equally 

 to axial boss, 1 free and short (left alar), 



3 (possibly 4) single (1 extra possibly 

 fused to last), 3 fused. 



A third specimen (diameter about 7.7 

 mm) has 22 majors with minors alternating 

 all around the somewhat deep, symmetrical 

 calyx. 



Transverse sections. — In very early 

 ephebic stage (diameters 1.7 by 1.9 mm) 

 holotype with solid central area joined by 

 1 cardinal, 1 lateral fused to next (right 

 alar), 10 majors, 1 (left) alar, 2 majors 

 next to cardinal, totaling 16 septa; sugges- 

 tion of tabulae. 



In section through bottom of another 

 calyx (diameters 14.0 by 7.7 mm), 22 

 septa, cardinal single, counter joined about 

 half-way on either side by other single ma- 

 jors. Tabular intersections abundant near 

 epitheca. 



Longitudinal section. — Columella very 

 long, tapering; tabulae steeply oblique 

 downwards to epitheca, both concave and 

 convex, generally very thin. 



Comparison. — This species differs notably 

 from R. calyculuju (Miller) emend. Easton 

 in having a columellar boss in the calyx; 

 otherwise the two are similar. 



Occurrence. — Localities 7, 9. 



Material. — Specimens studied, 8. Holo- 

 type, University of Cincinnati No. 24303 ; 

 figured paratypes, University of Cincinnati 

 Nos. 24304, 24305, 24306; figured ideo- 

 type, Illinois State Geological Survey No. 



