472 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



and in the disposition of the zooecia on the fronds. Possibly it should be considered 

 as only a subgenus. 



PLAGIOSMITTIA KEGULARIS Canu and Bassler, 1917. 



Plate 61, figs. 9-13. 



1917. Plagwsmittia rcgularis CANU and BASSLER, Synopsis of American Early Tertiary 

 Cbeilostome Bryozoa, Bulletin 96, United States National Museum, p. 51, pi. 5, fig. 4. 



Description. The zoarium is bilamellar; the fronds are flat, narrow bifurcated. 

 The zooecia are much elongated, distinct, separated by a thread or a furrow and 

 are much narrowed proximally. The frontal is flat or little convex and formed of 

 a tremocyst with numerous crowded pores. The peristome is thin, salient; the 

 apertura is semilunar with a very concave proximal border; the peristomice is 

 irregular, but it often contains a false rimule limited by the avicularium. The 

 ovicell is globular, little prominent; it is formed of a large circular area with 

 small numerous pores, surrounded by a smooth collar, little salient; it is imbedded 

 in the distal zooecia and opens into the peristomie. The avicularium is peristomial, 

 placed more or less laterally ; the mandible moves in the peristomie. 



f/ie=0.16mm. |Aa=0.06mm 



Measurements. reristomice < , Apertura , n ne 



[lpe=0.10 mm. [la=OM mm. 



Affinities. This species is quite constant on the whole; many zooecia, how- 

 ever, are marginated. 



It differs from Plagwsmittia porelloides in its larger dimensions (Lz=Q.75 

 and not 0.60 mm) and in its avicularium always placed laterally 'in the peristomie. 



It differs from Plagwsmittia virgula in its larger micrometric dimensions 

 (Ls=0.l5 and not 0.56 mm.) and in the absence of the large median avicularium. 



Occurrence. Middle Jacksonian: Wilmington, North Carolina (common). 



Upper Jacksonian (Ocala limestone) : Old Factory one-half mile above Bain- 

 bridge, Georgia (rare) ; west bank Sepulga River, Escambia County, Alabama 

 (common) ; Chipola River, east of Marianna. Jackson County, Florida (common). 



Cotypes.Czt. No. 62600, TJ.S.N.M. 



PLAGIOSMITTIA PORELLOIDES, new species. 



Plate 61, figs. 14-18. 



Description. The zoarium is bilamellar; the fronds are flat, narrow, bifur- 

 cated. The zooecia are much elongated, distinct, separated by a furrow or a salient 

 thread, much narrowed inferiorly; the frontal is flat or a little convex and formed 

 of a tremocyst with numerous and crowded pores. The peristome is thin, salient ; 

 the peristomice is oval ; the apertura is semilunar with a concave lower border. The 

 ovicell is little salient, imbedded in the distal zooecium; it is formed of a large 

 area with very fine pores, surrounded by a small, very thin collar; it opens into 



