NORTH AMERICAN EARLY TERTIARY BRYOZOA. 243 



De Gregorio in his Monograph on the Eocene of Alabama has created for the 

 group containing L. radiata, Lamarck, 1816, L. fenestrata De Gregorio, 1890, and 

 L. punctata Leymerie, 1845, a special genus Dimiclausa, in which L. ovata and 

 L. vemtcosa could be introduced. The essential character is the presence of hydro- 

 static cellules (cellulis medianis clausia). It is undeniable that the group of species 

 just cited forms a rather homogenous assemblage characterized chiefly by the great 

 development of the calcareous cryptocyst. But, though the hydrostatic cellules 

 may be constant, they are not peculiar to it, for hot only do they exist on many 

 other species of Lunularia. but they have the same constancy in the genus Trocho- 

 pora, where the mode of growth is totally different. These species of Lunularui 

 are perhaps identical or closely related forms, but they do not have different func- 

 tions from other species, so that they can not be separated generically. 



In the interior (fig. 9) the zooecia exhibit a convexity, often supporting the 

 ovicell. This convexity is characteristic of the genus. 



The larva always attached itself to a large grain of sand, which fact explains 

 the large number of hydrostatic zooecia permitting the zoarium to lighten itself 

 and thus escape the dangerous zone of the sand. 



In the transverse sections the very thick zoarium is formed of many celled 

 segments radiating from the center or from a bifurcation. 



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

 Eich Hill, Crawford County, Georgia ; 18 miles west of Wrightsville, Johnson 

 County, Georgia (rare) : 12 miles southeast of Marshallville, Georgia (rare) : Bal- 

 dock, Barnwell County, South Carolina (rare) ; 3 miles south of Perry, Georgia 

 (rare). 



Upper Jacksonian (Ocala limestone) : Chipola Kiver. east of Marianna. 

 Florida (rare); Bainbridge, Georgia (rare). 



Vicksburgian (" Chimney rock " of Marianna limestone) : One mile north of 

 Monroeville, Alabama. 



Cotypes. Cat. Nos. 63992, 63993, U.S.N.M. 



LUNULARIA LIGULATA, new species. 

 Plate 13, figs. 10-12. 



Description. The zoarium is a concave Lunulites. much expanded. The zooecia 

 are rectangular, transverse, distinct ; the mural rim is thick and distinct from the 

 cryptocyst, which is deep, smaller than the opesium, and very -finely granulated. 

 The opesium, orbicular or elliptical, is surrounded by a prominent collar. The ovicell 

 is a large distal convexity. The hydrostatic zooecia have a false opesium partially 

 obstructed by a wide calcareous tongue. The vibracula are elongated, narrow 

 fusiform, deeply embedded, disposed in distinct rows. The inner side lias flat or 

 slightly convex radial ribs, perforated with small, scattered pores. 



|/io=0.16 mm. . fZs=0.20mm. 



/ooeciai-, 



= U.:jO mm. 



Yibracula] 7 



Ui=0.10mm. 



