716 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
distance (0.40 and not 0.70 mm.) ; besides, according to the figures given by Canu 
in 1898, the ovicell is much more elongated. 1 
This species is also close to Plagioecia sub orbicularis Hincks, 1880, as it was 
figured by Canu in 1909, based upon specimens from the Lutetian ; but the micro- 
metric dimensions of the species are smaller than those of the American species. 
It differs from Microecia vibrio in its rectilinear (and not serpentiform) 
zooecia; in its peristomial diameter of 0.10 mm. (and not 0.08 mm.), in its incrust- 
ing zoarium (and not unilamellar) and finally in its larger ovicell. 
Occurrence. — Lower Jacksonian (Moodys marl) : Jackson, Mississippi 
(common). 
Middle Jacksonian: Wilmington, North Carolina (rare) ; near Lenuds Ferry, 
South Carolina (rare) ; Rich Hill, 51 miles southeast of Knoxville, Crawford 
County, Georgia (rare). 
Upper Jacksonian (Ocala limestone) : Red Bluff on Flint River, 7 miles above 
Bainbridge, Georgia (rare) ; Chipola River, east of Marianna, Jackson County, 
Florida (rare) ; Pachuta, Clarke County, Mississippi (very rare) ; Old Factory 
about 11 miles above Bainbridge, Georgia (common). 
Jacksonian (Zeuglodon bed) : Bluff on south side of Suck Creek, Clarke 
County, Mississippi (rare). 
Vicksburgian (Marianna limestone) : Salt Mountain, 5 miles south of Jackson, 
Alabama (rare). 
Cotypes. — Cat. Nos. 65305-65308, U.S.N.M. 
PLAGIOECIA MARGINATA, new species 
Plate 125, figs. 1-8. 
Description. — The zoarium is free, bilamellar, bushy, formed of undulated 
lobes branching in every direction. The tubes are distinct, elongated, flat, bordered 
by a salient thread, oval, arranged in irregular quincunx, striated transversally ; the 
peristome is orbicular or elliptical frequently closed by a smooth calcareous lamella, 
thin and little salient. The ovicell is convex, little transverse, suborbicular. The 
zone of growth is hardly visible. 
| Diameter of the peristome 0.14 mm. 
Measurements. — Diameter of the zooecia 0.20 mm. 
I Distance between the peristomes 0.70-0.90 mm. 
V aviations. — The peristomie of the tubes was much longer than usually found 
in these species ; a good specimen incrusted by a species of Floridina shows that it 
may be more than 1 millimeter in length. The unilamellar forms are not rare. 
Affinities. — This species much resembles Diastopora foliacea Lamouroux. 1821, 
of the Bajocian and Bathonian of Europe, but differs from it in its smaller micro- 
metric dimensions. 
Occurrence. — Middle Jacksonian: Near Lenuds Ferry, South Carolina (com- 
mon) ; Eutaw Springs, South Carolina (rare). 
Cotypes. — Cat. No. 65461, U.S.N.M. 
1 1898. Canu, Etude sur les ovieelles deu Bryozoaires du Bathonien d'Occaignes, Bulletin de la Soci£t£ 
Geologique de France, ser, 3, vol. 26, p. 260. 
