NORTH AMERICAN EARLY TERTIARY BRYOZOA. 301 



aspect the various species of this genus have the aspect of the more typical Gctleopsis. 

 If the family Galeopsidaf. Canu, 1913, is natural, it may become necessary to include 

 also the genus Gephyrotes, although at present we do not think so. 



GEPHYROTES LEVIGATUM, new species. 



Plate 6. figs. 1-4. 



Desmption. The zoarium incrusts shells. The zooecia are distinct, elongated, 

 aliform; the frontal is a convex gymnocyst encircling a cribriform area formed of 

 three or four pairs of costules without lateral median lacunae. All of the zooecia 

 bear an oblique spiramen. The aperture is elliptical, transverse, surrounded by 

 a thin, sharp peristome. The ovicell is embedded in the distal zooecia. rather large, 

 smooth, and globular. The two oral avicularia are rather large; their point is 

 directed toward the center of the aperture. One pair of lateral dietellae and a 

 distal dietella are present. 



,, /, ,7 =0.06-0.07 mm. 



Measurements. Aperture , 7 . 



[fa=0. 



.. 

 Aooecia 7 . no- /-IT i 



[fe=0.30-0.3o mm. (including avicularia). 



Variations. Our description agrees most with figure 1, which shows the gen- 

 eral aspect of our specimens. We have illustrated two others (figs. 2 and 3) of 

 a little different aspect. The gymnocyst is very small in figure 2 : it is absent in 

 figure 3; the costules are then larger. As the micrometric measurements, the 

 avicularia. and the ovicells are identical, we have not created a new species for 

 these less typical specimens. 



There are no lateral lacunae. The costules seem to us to be those of Mem- 

 branipon-llu, but we have not been able to discover their nature by a tangential 

 thin section because of the rarity of the specimens. The presence of the dietellae 

 would still be a reason for classifying the species in Mejnbraniporella. However, 

 the operculum appears to close the ovicell only when opening. 



The patient collector who will secure a score of specimens of this species and 

 of the following, will be sure of making important discoveries on the structure of 

 the Costulae. 



Affinities. This species differs from Gephyrotes sailtans in its less prominent 

 peristome and in its oral avicularia. which are much smaller (Lav 0.15 mm. and 

 not 0.25 mm.) and are lacking the calcareous pivot. 



In its smooth ovicell. it differs from Gephyrotes convexa and from Gephyrotes 

 spectdbilis. 



Occm r< in'''. Mitlwayan (Clayton limestone) : One mile west of Fort Gaines, 

 Georgia (rare). 



C'otypes.Cnt. No. (>:',si<;. T.S.X.M. 



GEPHYROTES SAILLANS, new species. 



Plate 5, figs. 18-20. 



Description. The zoarium creeps over algae. The zooecia are distinct, elon- 

 gated, separated by a furrow, aliform ; the frontal is a convex gymnocyst, encircling 



