836 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Gregory in 1909 distinguished the genera Petalrypora and Sparsicavea by their 
ovicells. Our new observations show no fundamental difference between the 
ovicells of these two old genera, which appear to be otherwise only zoarial aspects; 
we have included them in the genus Par ascosoecia. 
Genus ASCOSOECIA Canu, 1919. 
1919. Ascosoecia Canu, Etudes sur les Ovieelles des Bryozoaires Cyclostomes (2), Bulletin 
Societe Geologique de France, ser. 4, vol. 17, p. 347. 
The tubes are cylindrical. The walls of the mesopores are vesicular. 
Genotype. — Ascosoecia ( Zonopora ) ligeriensis D'Orbigny, 1852. 
Range. — N eocom i an - M id w ava n . 
In this genus it will be necessary to include the forms Zonopom , with bifur- 
cated mesopores (as Z. ligeriensis D’Orbigny, 1853) and Multicavea , with peri- 
stomes arranged in radial rows (as Multicavea magnified D’Orbigny, 1851). 
ASCOSOECIA PROMINENS, new species. 
Plate 108, tigs. 17-25. 
Description. — The zoarium is solid, arborescent, bushy, sometimes reticulate 
and borne on an expanded base. The tubes are cylindrical, bent horizontally at 
their extremity (in section). The peristomes are thin, orbicular, salient, irregularly 
arranged in quincunx. The mesopores are very small and polygonal. The ovicell 
is globular, very salient , orbicular. 
Diameter of the peristome 0.11-0.16 mm. 
Measurements. — Diameter of the ovicell 1.65 mm. 
Diameter of the branches 2.5 mm. 
This species is quite well characterized by its salient peristomes; but this 
character is easily lessened on the worn specimens. The number of tubes between 
the mesopores is irregular. In longitudinal section the mesopores are almost as 
wide as the tubes; they appear, on the contrary, much smaller in tangential section. 
There is probably a thickening of their walls at their extremity. The sections of 
this species are very difficult to interpret and its structure is still not clearly under- 
stood. 
Affinities. — Ascosoecia prominens differs from Tretocycloecia attenuata Ulrich, 
1882, in the thinness of the walls of the mesopores. 
Occurrence. — Midwayan (Clayton limestone) : Mabelvale, near Little Rock. 
Arkansas ( common ) . 
Cotypes. — Cat. No. 65410, U.S.N.M. 
ASCOSOECIA ? (ZONOPORA) ULRICHI, now species. 
Plate 110,. figs. 1-5. 
Description. — The zoarium is free, cylindrical, solid, bushy, or reticulate. The 
tubes are very long, cylindrical, bent at their extremity (in section). The peristomes 
are rather thick, nonsalient, grouped in quincunx in irregular, transversal zones. 
