NORTH AMERICAN L.ATER TERTIARY AND QUATERNARY BRYOZOA. 107 



• SCHIZOPODRELLA MARGINATA. new species. 



Plate 30, figs. 4, 5. 



Description. — The zoarium incrusts oysters. The zooecia are distinct, oval, 

 wide, bordered by a wide thread, little salient joined to the peristome; the frontal 

 is little convex and ornamented with large tremopores. The apertura is orbicular; 

 the rimule is wide, of little depth, triangular. The ovicell is little salient, much 

 embedded in the distal zooecium with a frontal area. On each side of the apertura 

 there are two small round avicularia without pivot. 



,, ^ , , \ha =0.10 mux. „ . fiz = 0.50mm. 



Measurements. — Apertura , _ ^„ ^ ,„ Zooecia , „ „„ . ^^ 



^ [ Za=0.0S-0.10 mm. ( fe= 0.28-0.40 mm. 



Affinities. — This small species is quite well characterized and easy to determine. 

 It differs from Schizopodrella pusilla, new species, in its great zooecial width and in 

 the triangular form of the rimule. 



Occurrence. — Pliocene (Waccamaw marl) : Waccamaw River, Horry County, 

 South Carolina (rare). 



Holotype.— Cat. No. 68569, U.S.N.M. 



SCHIZOPODRELLA DOVERENSIS Ulrlch and Bassler, 1904. 



Plate 18, figs. 1-3. 



1904. Schizopodrella doverenmVLmcn and Bassler, Bryozoa, Geological Survey Maryland, Miocene, 

 p. 421, pi. 117, fig. 1. 



Description. — Zoarium a thin sheet on foreign bodies, the figured specimen 

 growing on the reverse of Retepora doverensis. Zooecia well distinguished from 

 each other but with the surface rather flat; irregularly arranged, though their 

 elongate form gives some prominence to the longitudinal rows; average length 

 0.6 mm., width 0.35 to 40 mm. Orifice terminal, slightly transverse, broadly 

 notched on the proximal side, on the whole nearly circular. Surface reticulate, 

 only slightly convex, the central portion appearing flattened. Avicularia rather 

 small, prominent, one on either or both sides of the orifice, rarely wanting, situated 

 close to the peristome; apparently both divided by a septum. Ovicells not 

 observed. (Ulrich and Bassler.) 



Affinities.— -The zooecia are not always regularly oriented. The zoarium 

 incrusts shells or other bryozoa. 



This species differs from Schizopodrella unicornis Johnston, 1847, whose aper- 

 tura is identical, in its larger dimensions and in the absence of the frontal protru- 

 berance. It differs from Schizohrachiella {Escharella) sanguinea Smitt, 1872, in its 

 single very large avicularium and in the smaller and more numerous tremopores. It 

 differs from Stylopoma {Hippothoa) isahelleana Smitt, 1872, in the place of its 

 avicularium not situated below the apertura. 



Occurrence. — Miocene (Choptank formation) : Dover bridge, Maryland (rare) . 

 Pliocene (Caloosahatchee marl) : Shell Creek, De Soto County, Florida (very rare) . 



Plesiotypes.—C&i. No. 68570, U.S.N.M. 



