TRIP LOP HYLLITES 



39 



based upon the types of T. palmatus and 

 partly on Grove's hypotypes; University of 

 Chicago (Walker Museum), Nos. 31560, 

 31546, 4704, 25192, 31570, and cotypes No. 

 4705. Other materials studied by Grove: 

 holotype, Illinois State Geological Survey 

 (Worthen collection) No. 2562; plesiotype, 

 No. 2556. 



Taxonomic possibilities. — Triplophyllites 

 could be split into two subgenera, one of 

 which would have the same name as that 

 of the genus and would include Triplophyl- 

 lites with the cardinal fossula on the con- 

 cave side. The other subgenus would include 

 those corals with the cardinal fossula on the 

 convex side ; this, then, would include corals 

 corresponding to the concept of Zaphren- 

 toides Stuckenberg. Unless Zaphrentis re- 

 versa Worthen should prove to belong to 

 this group, the hypothetical subgenus is not 

 known at present in North America. 



Triplophyllites centralis 



(Milne-Edwards and Haime) 



Plate 9, figures 1, 2 



Zaphrentis centralis Milne-Edwards and Haime, 



1851, Mus. histoire nat., Arch., vol. 5, p. 



328, fig. 6. 

 Zaphrentis centralis, Milne-Edwards, 1860, His- 

 toire nat. des coralliaires, t. 3, p. 336. 

 Zaphrentis centralis, Worthen, 1890, Illinois 



Geol. Survey, vol. 8, p. 72, pi. 9, figs. 1, la. 

 Zaphrentis centralis, Williams, 1900, Arkansas 



Geol. Survey, Ann. Rept. 1892, vol. 5, pp. 



336, 337, 339-341. 

 Zaphrentis centralis, Keyes, 1894, Missouri Geol. 



Survey, vol. 4, p. 112. 

 Zaphrentis centralis, Keyes and Rowley, 1897, 



Proc. Iowa Acad. Sci., vol. 4, p. 30. 

 Zaphrentis centralis, Shepard, 1898, Missouri 



Geol. Survey, vol. 12, pt. 1, p. 122. 

 Triplophyllum centralis, Simpson, 1900, New 



York State Mus. Bull. 39, no. 8, p. 209. 

 Triplophyllum centralis, Simpson, 1902, New 



York State Univ. State Mus. Rept., vol. 54, 



no. 3, p. 209. 

 f Zaphrentis centralis, Girty, in Smith and Sie- 



benthal, 1907, U. S. Geol. Survey Folio 148, 



p. 6. 



Triplophyllum (Zaphrentis) centralis, Butts, 

 1922, Kentucky Geol. Survey, ser. 6, vol. VII, 

 p. 84. 



Zaphrentis centralis, Moore, 1928, Missouri Bur. 

 Geol. Mines, ser. 2, vol. 21, p. 189. 



fZaphrentis sp. aff. Z. centralis, Moore, 1928, 

 Missouri Bur. Geol. Mines, ser. 2, vol. 21, 

 pp. 181, 195. 



Zaphrentis centralis, Cline, 1934, Bull. Amer. 

 Assoc. Petrol. Geol., vol. 18, no. 9, p. 1152. 



Externals. — Medium to large, curved cer- 

 atoid; epitheca thin, with encircling swell- 

 ings, faint interseptal ridges, septal grooves ; 

 calyx deep, steep-walled ; prominent cardinal 

 fossula on concave side. 



Transverse sections. — In late ephebic 

 stage, about 40 major septa, radially ar- 

 ranged, withdrawn from center; septa of 

 counter quadrants thickened ; cardinal sep- 

 tum rudimentary; tabulae and dissepiments 

 present; minor septa as septal ridges; alar 

 fossulae indistinct or lacking. 



In middle ephebic stage 36 thick major 

 septa, all except very short cardinal septum 

 extend to center or fuse about narrow car- 

 dinal fossula ; alar fossulae much reduced ; 

 minor septa present ; dissepiments sparse. 



In early ephebic stage about 30 thin major 

 septa, arrangement is radial in counter 

 quadrants, pinnate in cardinal quadrants; 

 alar fossulae well developed; cardinal sep- 

 tum very short; cardinal fossula narrow 

 bounded by thin walls. 



In neanic stage, 26 major septa, cardinal 

 septum long, thick; cardinal fossula long, 

 widest axially, with thick wall, composed of 

 ends of pinnate septa in cardinal quadrants ; 

 septa in counter quadrants radial; alar fos- 

 sula not pronounced; dissepiments very 

 sparse. 



Occurrence. — Localities 17-21, 70, 74, 

 84, 86, 87, 89, 97, 101-106. 



Material. — Specimens studied, 4. Grove's 

 hypotypes. University of Chicago No. 

 31560; Worthen's specimens, Illinois State 

 Geological Survey (Worthen collection) 

 Nos. 2570, 2563 ; primary types are pre- 

 sumably in Paris, France. 



Remarks. — This species can be distin- 

 guished by the axial retreat of septa in the 

 counter quadrants, by the failure of septa 

 to curve about the cardinal fossula in adult 

 stage, and by the relatively smooth but 

 never spinose epitheca. 



Triplophyllites cliffordanus 

 (Milne-Edwards and Haime) 



Plate 9, figures 3-5 



Zaphrentis cliffordana Milne - Edwards and 

 Haime, 1851, Mus. histoire nat. Arch., vol. 

 5, p. 329, pi. 3, fig. 5. 



Zaphrentis cliffordana, Milne-Edwards, 1860, 

 Histoire nat. des coralliaires t. 3, p. 337. 



