284 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
known; it may have been very thin like Philhedrella and therefore not well 
preserved. 
The name Choniopora may preoccupy the present one as already pointed out 
by Williams, but until the interior of that genus is made known Williams’ ge- 
neric name is preferred. Choniopora was originally thought to be a bryozoan 
colony but was later shown by Geinitz to have the shell structure of the Craniidae; 
the internal musculature still remains unknown. 
ACANTHOCRANIA CUMBERLANDENSIS (Foerste) 
Plate 26, D, figures 9-11 
Crania granulosa cumberlandensis Forrste, Bull. Sci. Lab., Denison Univ., vol. 16, p. 41, 
pl. 5, fig. 8, r9ro. 
Types.—Lectotype: 87157a; paratypes: 87157b (c, Foerste, 1910). 
Horizon and locality—Wells formation in Tennessee: 14 miles southwest of 
Cumberland City, in Stewart County. 
ACANTHOCRANIA ERECTA Cooper, new species 
Plate 26, G, figures 16, 17 
Shell known only from brachial valve, of about medium size for the genus, 
nearly circular in outline, subconical in profile and with a nearly central apex. 
Sides flat in profile, moderately steep. Surface covered by short, blunt spines. 
Measurement in mm.—Holotype, length 9, width 9.5, height 4. 
Type.—Holotype: 109789. 
Horizon and locality—Bromide formation (Mountain Lake member?) in 
Oklahoma: NW43 sec. 27, T. 1 S., R. 2 E., midway between Dougherty and 
Davis. 
Discussion.—This species can be distinguished readily from A. granulosa and 
A. setigera by its nearly symmetrically conical form and profile and by the 
greater height of the cone. The single specimen representing this species is also 
marked by low ridges, produced by the uneven surface of the host, which ex- 
tend from the posterior side to the anterior side. 
ACANTHOCRANIA GRANDIS Cooper, new species 
Plate 26, A, figures 1-3 
Species known from brachial valve only; large for the genus, crudely trans- 
versely elliptical in outline; conical in both profiles; later profile unsymmetri- 
cally conical, the anterior slope long and gently convex; posterior slope short, 
steep, and concave; apex located about one-fifth the length from the posterior 
margin ; break smooth and slightly curved. Anterior profile a symmetrical cone 
with straight and steep sides. Surface covered by spines about 1.25 mm. in length. 
Measurements in mm.—Holotype, length 15.2, width 17.4, height 6.6. 
Type.—Holotype: 116838. 
Horizon and locality—Base of Benbolt formation in Virginia: On the west 
