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 suborbicularis 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 vibri.o 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) ; Kich Hill, 5| miles southeast of Knoxville, Crawford 

 County, Georgia (rare). 



Upper Jacksonian (Ocala limestone) : Eed Bluff on Flint River, 7 miles above 

 Bainbridge, Georgia (rare) ; Chipola Eiver, east of Marianna, Jackson County, 

 Florida (rare) ; Pachuta, Clarke County, Mississippi (very rare) ; Old Factory 

 about 14 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.Czt. 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. 



Diameter of the zooecia 0.20 mm. 



Distance between the peristomes 0.70-0.90 mm. 



Variations. 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 Dinxtopora foliacca 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 ovicelles deis Bryozoaires du Batbonien d'Occaignes, Bulletin de la SoeielS 

 Geologique de France, ser. 3, vol. 26, p. 260. 



Measure m e i its. 



