NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
119 
characters of the Membranipore group and not of the Onvchocellidae. The dorsal 
olocyst is very thin and easily worn away, allowing the substratum to appear. AVe 
have observed some cases of total regeneration and deformed zooecia are not rare. 
A-ffvnities . — It may be that this species ought to be classed in Ilincksina; 
however, the great development of the cryptocyst and the entire absence of 
avicularia will not allow us to place it there. This is a problem which can find its 
solution only in the study of an identical or closely allied recent species. 
The zooecia resemble those of Amphiblestrum pcrfragile MacGillivray, 1868, 
figured by Ortman in 1890. The present species differs in its nonbilamellar zoarium 
and in the absence of a large interzooecial avicularimn. MacGillivrav’s species may 
belong to a new genus. 
Occurrence .— Middle Jacksonian: Near Lenuds Ferry, South Carolina (com- 
mon) ; AVilmington, North Carolina (very rare) ; Eutaw Springs, South Carolina 
(rare). 
Holotype. — Cat. No. 63885, U. S. N. M. 
OGIVALINA ELONGATA, var. MINOR, new variety. 
Plate 23, figs. 9, 10 
This variety is well founded, for no intermediate specimens have been noticed. 
However, it can not be considered a smaller distinct species, for it occurs at the 
same localities as the species itself. 
M easurements . — Opesia 
j ho— 0.25-0.50 mm. 
I lo— 0.17-0.20 mm. 
Zooecia 
Zs=0.40-0.43 mm. 
lz= 0.22—0.26 mm. 
Occurrence . — Middle Jacksonian: AVilmington, North Carolina (rare); near 
Lenuds Ferry, South Carolina (rare) ; Eutaw Springs, South Carolina (rare). 
Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 
Cotypes. — Cat. No. 63886, U.S.N.M. 
Genus MEMBRENDOECIUM Canu and Bassler, 1917. 
1917. Membrendoecium Canu and Bassler, Synopsis of American Early Tertiary Cheilos- 
tome Bryozoa, Bulletin 96, United States National Museum, p. 17. 
Ovicell endozooecial. Small simple interopesial avicularia. Dietellae present. 
No spines. 
Genotype. — Amphiblestrum papillatum Busk, 1884. 
Range. — Midwayan — Recent. 
In Membrendoecium we have a yery natural genus with exact characters. The 
recent species Amphiblestrum papillatum is closely related to our fossil forms, but 
unfortunately this species is very rare and its structure is imperfectly known. Its 
avicularia have much the aspect of our species, and Busk writes of it “ Small avicu- 
laria having a triangular mandible on small papillary eminences seated in the 
angular interzooecial spaces.” 
In its exterior aspect this genus recalls Pyriporella Canu, 1911, but the latter 
has hyperstomial ovicells. The structures which Canu has identified as vibracula 
