38 



CHOUTEAU CORALS 



this genus but subsequently (1915a, p. 23) 

 stated that his concept of Mejiophyllum co- 

 incided with Triplophyllum Simpson ; ac- 

 tually, it is to be inferred from this that 

 his identification implies Triplophyllites. 

 Until the genoholotype of Menophyllum is 

 studied, it is suggested that the name not be 

 applied to other Carboniferous ''zaphren- 

 tids." 



(4) Triplophyllum Simpson, 1900 was 

 proposed with Z. terehrata Hall, 1883 as 

 genotype. The single available specimen was 

 not sectioned ; in fact, only a side view was 

 figured. Simpson figured Z. dalei Milne- 

 Edwards and Haime and gave Z. centralis 

 Milne-Edwards and Haime as an example, 

 but he chose Z. terehrata as genotype ap- 

 parently because that type was in the col- 

 lections he studied and the others were not. 



Girty (1915a, p. 23) erroneously cited 

 ''T . centrale" as the type species of Triplo- 

 phyllum. Although it appears that subse- 

 quent studies correctly name the genotype, 

 it so happens that Z. terehrata is not at all 

 typical of the concept of Triplophyllum of 

 authors exemplifying the generic group oc- 

 curring in the Carboniferous. 



The writer was unable to borrow the 

 genoholotype of Triplophyllum for study, 

 but excellent photographs were furnished 

 by Dr. Winifred Goldring, some being re- 

 produced here. Through the courtesy of 

 Mr. H. E. Vokes, the writer was allowed 

 to study and section four additional speci- 

 mens (topotypes) of the species. So far as 

 the writer is aware, these five are the only 

 known specimens of T. terehratum (Hall). 

 The material examined shows external de- 

 tails fairly well, but the internal preserva- 

 tion is very poor. A new description of this 

 species is as follows. 



Triplophyllum terebratum (Hall) 



Plate 11, figures 1, 2; Plate 17, figures 16-18 



Large, nearly straight, ceratoid ; calyx 

 very deep, secondary septa prominent wher- 

 ever seen, primaries tending to form counter- 

 clockwise axial vortex; cardinal fossula in- 

 conspicuous in calyces, not confined to either 

 concave or convex side, bounded by un- 

 fused adjacent metasepta, occupied by short 

 cardinal septum; alar fossulae either absent 

 or doubtfully identified septa withdrawn 

 from axis in very old corallites, leaving cal- 

 ical floor formed by a tabula; epitheca thin, 



wrinkled, showing interseptal ridges and 

 septal grooves faintly when unweathered ; 

 holotype with 48 major septa; another il- 

 lustrated specimen with 42 primaries alter- 

 nating with shorter secondaries, another 

 with 44 primaries alternating with secon- 

 daries. In late ephebic stage (diameters 23 

 by 18 mm) primaries extend nearly to cen- 

 ter, but are bunched; tabulae slope steeply 

 into cardinal fossula; dissepiments abun- 

 dant. In late neanic or early ephebic stage 

 (diameters 11.5 by 11.5 mm) most primary 

 septa extend to center, tendency toward ax- 

 ial vortex pronounced, cardinal fossula 

 prominent, cardinal septum long, only one 

 of alar fossulae discernible; secondary septa 

 rudimentary or very short; dissepiments 

 sparse. 



Of the foregoing characters, the most im- 

 portant are the tendency toward formation 

 of an axial vortex, the cardinal fossulae 

 with free metasepta along the walls, the 

 inconsequential alar fossulae, and the 

 bunched groups of septa in late stages. Of 

 less importance are the extremely deep calyx, 

 the abberant position (with regard to curva- 

 ture of the specimen) of the cardinal fos- 

 sula, and the relatively long secondary septa 

 associated with very long and free primary 

 septa in the calyx. 



These characters necessitate the recognb 

 tion of two genera, Triplophyllum, and 

 Triplophyllites. Triplophyllum contains two 

 American species — the Onondagan T. tere- 

 hratum (Hall) and T. edwardsi (Nichol- 

 son). Triplophyllites contains the Carbon- 

 iferous species heretofore thought typical of 

 Triplophyllum. 



The presence of dissepiments in Triplo- 

 phyllites must be considered in relation to 

 phylogenetic development, for this character 

 is not consistent within the genus and may 

 be difficult to prove in many specimens. Dis- 

 sepiments are more apt to be found in strat- 

 igraphically older species, although they oc- 

 cur sparsely and irregularly and sometimes 

 in modified form in younger species. Thus, 

 although the writer's diagnosis is based in 

 part upon a character of diminishing 

 strength, the presence of the character in 

 the series is of great taxonomic value. 



Material. — Genoholotype of Triplophyl- 

 lum; New York State Museum No. 

 3841/1 ; studied plesiotypes; American Mu- 

 seum of Natural History No. 4094/1. The 

 present understanding of Triplophyllites is 



