86 
ANNALS NEW YORK ACADEMY OF SCIENCES 
Worthen ( loc . cit.) describes the species thus: 
Corallum small, turbinate, pointed below, and slightly curved; epitheca thin, 
external striae distinct; height of corallum one inch; breadth of cup f inch; depth 
of same \ inch. 
Septal fossette nearly central, and extended on the side of the greatest curva¬ 
ture; primary lamellae comparatively strong, and numbering about 26, all reaching 
the thickened border of this septal fossette. 
Quite common in the Keokuk limestone at Warsaw, Hamilton, Nauvoo and 
Keokuk. 
The specimens studied and figured in this paper were from Lanesville, 
Ind. 
This species, in so far as the characteristic inner wall is concerned, shows 
Figs. 15-16. Hapsiphyllum spinulosum. X 4. 
Figs. 17-19. Hapsiphyllum varsoviense. X 4. 
an advance over Hapsiphyllum calcareforme and II. spinulosum The 
three sectional views figured are from three different stages of three individ¬ 
uals and show the manner of individual development and change from the 
Hapsiphyllum calcareforme condition, which is almost identical with figure 
