528 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Affinities. We have not found the ovicell of this extremely rare species and 

 its generic determination naturally remains somewhat doubtful. 



We have already mentioned the presence of analogous avicularian zooecia in 

 Porella planulata and in Metroperiella grandipora. 



The great narrowness of its zooecia absolutely characterizes this species and 

 does not permit it to be confused with any other. 



Occurrence. Middle Jacksonian; Near Lenuds Ferry, South Carolina (very 

 rare) ; Baldock, Barnwell County, South Carolina (very rare). 



nolotypeG&i. No. 64177, U.S.N.M. 



CHEILOPORA GRANDIS, new species. 



Plate 68, figs. 3-5. 



Description. The zoarium is unilamellar and creeps over algae. The zooecia 

 are very large, ogival, separated by a salient thread ; the frontal is somewhat convex 

 and perforated with numerous tremopores. The apertura is oval, elongated; two 

 triangular cardelles separate a large semilunar anter from a smaller convex poster. 

 On each side of the apertura are two salient avicularia with pivot, symmetrically 

 placed. 



[Aa=0.30mm. ,, . (7:3=1.00-1.25 mm. 



Measurements. Apertura 7 _ Zooecia] A7niop;rv 



(?<z=0.27mm. |t?=0.70-l.'2omm. 



Variations. As in all the species which are attacked by gigantism, a disease 

 which the bryozoa as well as other organisms suffer, as shown by Larger, this 

 also is quite variable in its micrometric measurements. Very often the zooecia are 

 elongated, and the width oscillates between 0.70 and 0.80 mm. The length, some- 

 what more constant, is never lower than 1 mm. On the dorsal face of the zoarium 

 the zooecia have exactly the form of a more or less elongated lozenge. 



We are ignorant of the ovicell, but the generic determination does not offer 

 any doubt. 



Affinities. This species differs from Cheilopora saillans in its much larger 

 micrometric dimensions and in its unilamellar zoarium. 



It differs from Cheilopora transversa in its elongated and nontransverse aper- 

 tura. 



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

 3J miles north of Grovania, Georgia (rare) ; 4r| miles southeast of Marshallville, 

 Georgia (very rare). 



Cof.ypes.~Cnt. No. 64174, U.S.N.M. 



CHEILOPORA SAILLANS. new species. 



Plate 68, figs. 9-11. 



Description. The zoarium is free, bilamellar, formed of two lamellae, back 

 to back, and more or less separable. The zooecia are distinct, elongated, lozenge- 

 shaped, separated from each other by a thick, very salient thread; the frontal is 

 somewhat convex and formed of a tremocyst on a thin perforated olocyst. The 



