NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
721 
DESMEPLAGIOECIA (ACTINOPORA) TENUIS Reuss, 1869. 
Plate 155, figs. 1-6. 
ISG4. Defrancia monosticha Reuss, TJeber Antliozoen nnd Bryozoen der Mainzer Tertiar- 
beekens, Sitzungsberichte der k. Akademie der Wissenschaften, Wein, vol. 50, p. 11, 
pi. 3, fig. 1. 
1869. Discosp.arsa tenuis Reuss, Palaontologische Studien fiber die alteren Tertiarschichten 
der Alpen, Crosaro, Denksehriften der k. Akademie der Wissenschaften, Wien, 
vol. 29, p. 280, pi. 34, figs. 9, 10. 
1869. Discosparsa regularis Reuss, Idem, p. 2S0, pi. 34, fig. II. 
1887. Discosparsa tenuis Pergens, Note preliminaire sur les Bryozoaires fossiles de 
environs de Ivolesvar, Bulletin de la Soeiete royale Malacologique de Belgique, 
vol. 22, p. 37. 
1892. Diastopora tenuis Waters, North Italian Bryozoa, Cyclostomata, Quarterly Jour- 
nal of the Geological Society of London, vol. 47, p. 154. 
Description. — The zoarium is free, discoidal, pedunculate or not. The fascicles 
are salient, very close together, arranged radially, almost continuous. The tubes 
are indistinct; the peristome is orbicular or quadrangular. The ovicell is very 
long, convex, parallel to the zoarial margin. The zone of growth is narrow. The 
lower face is concave, striated concentrically. 
| Diameter of the peristome 0.13 mm. 
Measurements. — j Separation of the fascicles 0.13 mm. 
I Diameter of the zoaria 3.00-6.00 mm. 
Affinities. — Our determination has been based on the figures and not upon 
German specimens. In aspect our figures are similar to those of Defrancia mono- 
sticha Reuss, 1861, but the American zoaria are larger. We see no difference from 
Discosparsa tenuis Reuss, 1869. 
This species differs from D esm,eplagioecia brevis in its fascicles, which are con- 
tinuous and not interrupted, and in its free zoarium. It differs from Desme- 
plagioecia tenuissima in its larger zoarial diameter. 
Occurrence. — Vicksburgian (Marianna limestone) : One mile north of Mon- 
roeville, Alabama (common). 
Geological distribution. — Priabonian of Vicentin (Reuss, Waters) and of 
Kolosvar (Pergens) ; Rupelian of Germany (Reuss). 
Plesiotypes. — Cat. No. 65469, U.S.N.M. 
DESMEPLAGIOECIA (ACTINOPORA) TENUISSIMA, new species. 
Plate 126, figs. 8-10. 
Description. — The zoarium is discoidal, free or incrusting shells, eccentric. 
The fascicles are very thin , arranged radially, very salient, discontinuous. The 
tubes are invisible ; the peristome is thin, orbicular, or rectangular. The ovicell is 
very long, thin, little convex. The zone of growth is thick and rather wide. 
( Diameter of peristome 0.08 mm. 
Measurements. — I Separation of the fascicles 0.12-0.15 mm. 
| Diameter of the zoaria 0.7 mm. 
55899— 20— Bull. 106 46 
