344 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
The known fossil species of this genus are : 
Stephanosella. ( Lepralia ) entomostoma Reuss, 1847. 
Stephanosella ( Lepralia ) s eriata. Reuss, 1874. 
Stephanosella strictifissa MacGillivray, 1895. 
The genotype SchizoporelZa biaparta Michelin, 1845, lives to-day off the Azores 
(Norman), in the waters of Florida (Smitt), and off the eastern coast of the 
United States (Osburn). The currents have also carried the species along the 
western coasts of the United States (Roberston). 
The simultaneous occurrence in Europe and America of Stephanosella ( Schizo - 
porella) entomostoma Reuss, 1847, shows again that the equatorial currents were 
already in existence in the Vicksburgian age. 
A-D. Stephanosella biaperta Michelin, 1845. A. Zooecia, X 30. B. Zooecia with ovicells 
and avicularia, X 30. (After Hincks, 1880.) C. Operculum of the variety divergens. (After 
Norman, 1903.) D. Operculum, X 85. inf, muscular insertion. 
E. Mandible, X 85. (After Nordgaard, 1906.) 
STEPHANOSELLA PARVIPORA, new species. 
Plate 85, fig. 22. 
Description . — The zoarium incrusts bryozoa. The zooecia are distinct, some- 
what elongated, subhexagonal, irregular; the frontal is smooth, little convex, 
bordered by widely spaced, very small areolae. The aperture is very small, trans- 
verse, and is provided with a wide rimule. The ovicell is large, salient, sur- 
rounded by a collar. One or two irregular, oral avicularia are placed at dif- 
ferent heights and deform the zooecia. 
Measurements . — Aperture 
j ha=0. (400.045 mm. 
{ ?<7,=0.06-0.07 mm. 
Zooecia 
Ls= 0.35 mm. 
Is— 0.25 mm. 
Affinities . — The frontal of the ovicell is very fragile and does not always 
exist on the fossils ; only the outer collar persists. 
This species differs from Stephanosella entomostoma Reuss, 1847. in its much 
smaller aperture (la= 0.06 mm. instead of 0.12 mm.). Its other micrometric 
dimensions are also much smaller than those of Stephanosella (Schisoporella) 
biaperta Michelin, 1845. 
Occurrence . — Vicksburgian (Marianna limestone) : Three miles southeast of 
Vosburg, Jasper County, Mississippi (rare). 
Holotype. — Cat. No. 64270. IT.S.N.M. 
