72 
ANNALS NEW YORK ACADEMY OF SCIENCES 
1874 Heterophrentis prolifica Billings, Canadian Naturalist, (new series), vol. 
VII, No. 4, Mar. 1874. 
The authoritative description of this species is as fellows 1 : 
Fig. 18. Stereolasma rectum. (Enlarged.) 
Fig. 19. Stereolasma rectum. (Enlarged.) 
Corallum simple, turbinate, curved, expanding to a width of from 18 to 24 lines 
in a length of from two to four inches. Surface with a few undulations of growth. 
1 E. Billings, Can. Nat., (new series), Vol. VII, No. 4, p. 236, Mar., 1874. 
