738 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
pendicularly to the zoarial margins and their traces are indicated in thin sections 
by their peculiar undulations (fig. 16) regularly spaced. The reader will better 
comprehend this peculiar arrangement by consulting figure 12 which shows the 
interior of the tubes obtained by the ablation of one of the two lamellae of the 
zoarium. 
The oeciostome is smaller than a tube as in the genus Microecia , hut it is turned 
toward the base; it is isolated and is never supported on the peristome of a tube. 
In spite of the large transverse wrinkles which ornament the tubes, the tan- 
gential section indicates that their walls are absolutely identical with those of all 
the other Cyclostomata (fig. 11). 
When the transverse section is indeed perpendicular at the time of the folding 
and at the zone of growth (fig. 11), the tubes adjacent to the basal lamella are 
alone visible. In the other case the tubes appear formed on the basal lamella and 
above their ramifications form the peristomial lines (fig. 16). 
Affinities. — This species differs from Reticulipora nuramulitorum D’Orbigny, 
1852, and from Reticulipora plicata Canu, 1909, of the French Lutetian, in its dif- 
ferent. micrometric measurements and in its larger wrinkles. Moreover, the ovicells 
of the two latter species are not known. 
This species is quite characteristic of the Vicksburgian. 
Occurrence. — Vicksburgian (Red Bluff clay) : Seven and one-half miles south- 
west of Bladen Springs, Alabama (rare) ; one-fourth mile west of Woodward, 
V T ayne county, Mississippi. 
Vicksburgian (Marianna limestone) : Murder Creek, east of Castlebury, 
Conecuh County, Alabama (common) ; west bank Conecuh River, Escambia 
County, Alabama (common) ; Salt. Mountain, 5 miles south of Jackson, Alabama 
(very rare) ; near Claiborne, Monroe County. Alabama .(common) ; one mile north 
of Monroeville, Alabama (very common). 
Cotypes. — Cat. No. 65405. U.S.N.M. 
Family DIAPEROECIIDAE Canu, 1918. 
Anatomical bibliography . — 1887. Waters, On tertiary Cyclostomatous Bryozoa, Quarterly Jour- 
nal of tlie Geological Society, vol. 43, pi. 18, figs. 5, 6, 13, 14. 15. — 1903. Waters, Bryozoa 
from Franz Josef Land, Journal Linnean Society, London, vol. 28, p. 173, pi. 19', ligs. 1-13. — 
1905. Waters, Bryozoa from near Cape Horn, Journal Linnean Society. London, vol. 29, p. 247, 
pi. 29, figs. 10-14. — 1914. Waters, The Marine Fauna of British East Africa and Zanzibar, 
Proceedings of the Zoological Society of London, p. 836. 
The ovicell is formed after the calcification of the distal tubes. It is an irreg- 
ular, subglobular elevation, placed among many tubes which project on the ovicell 
itself. The oeciostome is submedian, transverse, salient, often isolated, generally 
proximally directed. 
We do not know the larva, but this family appears different from the Tubu- 
liporidae in its oeciostome which is often isolated and in its expansion bv which it 
completely surrounds the tubes or the fascicles. 
