244 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Variations. The hydrostatic zooecia which surround the ancestrula are very 

 variable. The small tongue, which partially obstructs the false opesium, is more 

 or less developed; it becomes transformed into a median column and it is then 

 bordered by four small symmetrical pores. It is evident that the lateral fissures 

 are opesiules through which the parietal muscles pass. 



Affinities. This species differs from Lunularia verrucosa in its larger micro- 

 metric dimensions and in its hydrostatic zooecia. which are not wartlike. but are 

 ornamented with a small tongue. 



Although closer still to Lunularia radiata Lamarck 1816, it differs from it in 

 its smaller micrometric measurements (Zs=0.20 mm. instead of 0.36 mm.), and 

 in its transverse, and not elongated zooecia, and in its hydrostatic zooecia furnished 

 with a tongue. 



It belongs to the group Dimiclausa De Gregorio, 1890, for which we have as 

 yet no constant characteristics. 



Occurrence. Lower Jacksonian: 3i miles southeast of Shell Bluff post office, 

 Georgia( rare). 



Claibornian (Cook Mountain formation) : Moseleys Ferry, Calclwell County, 

 Texas (very common). 



Lower Jacksonian (Moodys marl) : Jackson, Mississippi (abundant). 



Jacksonian (Zeugloclon zone) : Bluff on south side of Suck Creek, Clarke 

 County, Mississippi. 



Vicksburgian (Red Bluff clay) : Red Bluff. Wayne County, Mississippi (rare). 



Cotypes.C&i. No. 63846, U.S.N.M. 



LUNULARIA FENESTRATA De Gregorio, 1890. 

 Plate 37, figs. 10-13. 



1890. Dimiclausa fenestrata DE GKEGOEIO, Monographic de la Faune Eocenique de Alabama. 

 Ann.iles de Geologie, et de Paleontologie, Livraisons 7, S, p. 249, pi. 42, figs. 23-27. 



Description. The zoarium is a small, convex, expanded Lunulites with the 

 zooecia and vibracula in distinct, alternating radial rows. The zooecia are rec- 

 tangular, somewhat transverse, distinct, ogival ; the mural rim is thick ; the crypto- 

 cyst very small; the opesium large, elongated, elliptical. The ovicell is a large 

 distal convexity. The ancestrular zooecia are hydrostatic and calcified with four 

 opesiular openings like a window. The vibraculum is long, narrow, fusiform, deep, 

 primoserial in the middle, but in distinct rows along the margins. The inner side 

 is formed of large, radial, convex ribs with small pores far apart. A large, distal 

 septula and two pairs of large, lateral septulae are present. 



,, . fA0=0.20mm. . \La= 0.22-0.26 mm. 



Measurements. (Jpesia , ... Zooecia , . n 



120=0.14 mm. lZs=0.24-0.26mm. 



Affinities and variations. As we have not observed a polypidian convexity 

 or an opesiule, we can not affirm that this species should be classed in the Coilostega ; 

 but on account of its resemblance to Lunularia distans Lonsclale 1845, we must 



