25 
Remarks . The specimens of Hapsiphyllum in our collection are poorly 
preserved, but the comparatively slow increase in diameter of corallum 
and the elongate inner wall are more characteristic of H. calcareforme than 
of any other species of the genus. The number of secondary septa is, 
however, exceedingly variable, from two or three to a number equalling 
that of the primary septa. Different species may here be represented, or 
the varying specimens may merely represent stages in the growth of a 
single species. The former supposition seems at present the more prob- 
able since variations in number and length of secondary septa, in extension 
of fossula to or beyond the centre of the calyx, etc., occur upon individuals 
of almost the same size. 
Locality and Horizon. Mississippian (Warsaw and St. Louis) of Ken- 
tucky, Indiana, etc. In the Minnewanka region in the Pennsylvanian of 
sections 1-31 (r), 33 (r) ; 2-2 (r), 8 (r), 15 (r) ; 3-7 (c), 10 (c); 3a-l (c) ; Missis- 
sippian of sections 2-22 (R), 24 (r), 25 (r); 4-3 ? (C). 
Genus, Triplophyllum Simpson 
Triplophyllum dalii (Edwards and Haime) ? 
1851. Zaphrentis dalii Milne-Edwards and Haime, 1851, Mon. des 
Polyp. Foss., p. 329; Z. spinulifera Hall, 1858, Geol. Iowa, vol. 1, 
pt. 2, p. 650, Pi. 22, figs, la, b; Z. dalii Worthen, 1890, Geol. Surv., 
111., vol. 8, p. 71, PI. 10, figs. 12, 12a; Keyes, 1894, Mo. Geol. Surv., 
vol. 4, p. 113, PI. 15, fig. 12. 
Remarks. A single fragment in our collections appears to belong to 
this species. It has a diameter of 35 mm. and a preserved tapering length 
of 20 mm. It has 60 septa, no secondary ones, a straight-sided fossula 
reaching the centre of the calyx, and two pseudo-fossulse. Whether the 
fossula is upon the convex or concave side cannot be seen. 
Locality and Horizon. Lower and Middle Mississippian (Burlington 
to St. Louis) of the Mississippi valley. In the Minnewanka region in the 
Pennsylvanian of section 2a-14 (R). 
Triplophyllum minnewankensis n. sp. 
Plate Y, figures 1, 2 
Description. Corallum cone-shaped, regularly and considerably 
curved to slightly curved, exhibiting irregular contractions at intervals. 
Fossula well marked, narrow, reaching the centre; it is situated upon the 
side of greatest convexity. Alar fossulee present, though poorly developed. 
Primary septa somewhat sinuous, 60 to 80 in number; they mostly reach 
the centre. With these primary septa there alternate at the margin of the 
calyx an equal number of secondary septa which are short — usually about 
4 mm. long. Height of calyx 40 to 60 mm.; diameter 20 to 35 mm. Some 
incomplete specimens, which apparently taper more gradually, may have 
attained a length of 10 cm. Dissepiments moderately numerous. 
Remarks. This species is similar to T. dalii Edwards and Haime from 
the Mississippian of the Mississippi valley. Their description, however, 
and the figures later given by Worthen 1 of a specimen from the same 
i Geol. Surv., 111., vol. 8, 1890, PI. 10. 
