22 University Geological Survey of Kansas. 



TRACHYPORA. 



Milne-Edwards and Haime, Pol. Foss. d. Terr. Pal., p. 305, (1851). 



Trachypora austini. Plate V, fig. 8: plate VI, figs. 7-7b. 



Trachypora austini Worthen, Geol. Surv. 111., viii, p. 81, pi. xi, ff. l-ld y 

 (1890). 



Worthen's description: " Corallum dendroid, the branches 

 generally cylindrical, sometimes irregular, from 15 to 25 mm. 

 in diameter, and infrequently divided. Corallites conical, 

 diverging from an imaginary axial line to open on all parts 

 of the free surface. The calyces all oval or circular, very 

 variable in size, the larger ones 1.1 mm. in diameter, and 

 either level with the general surface, or with an elevated mar- 

 gin. Each orifice is adorned with small tubercles or short 

 ridges arranged in a radiate manner around the calyx margin. 

 Openings of the corallites separated by dense calcareous tissue 

 of variable thickness, but apparently always as wide as, or 

 wider than, the diameter of the tube orifices. Sections show 

 that the tubes are prismatic and in contact with each other, 

 that their walls are greatly thickened by a calcareous deposit 

 on the inner side of the tubes, and that the amount of thick- 

 ening increases toward the orifices. Mural pores of large size 

 are present, but apparently not numerous. Tabulae are best 

 developed in the axial region, where they cross the tube cavity 

 at intervals equaling once or twice the diameter of the tubes. 

 Tangential sections show that the corallite cavities are sur- 

 rounded by blunt, thick, septal ridges. The walls are now com- 

 posed of fibro-crystalline calcite, and the change has destroyed 

 the finer details of structure." 



Range and distribution: "Coal Measures; Labette county r 

 Kansas." 



" In all important respects the species described here re- 

 semble the Trachypora ornata Rominger sp., from the Hamilton 

 group, and I do not think any reasonable objection can be urged 

 against placing them in the same genus. Specifically they are 

 quite distinct, the corallum of Rominger's species being much 

 smaller, the 'corallites much less variable in size and not so 

 prominently margined, nor are the interspaces so thick." 



