16 BULLETIN 96, UNITED STATES NATIONAL MUSEUM. 



Occun^ence. — Middle Jacksonian : Rich Hill, 5^ miles southeast of 

 Knoxville, Crawford County, Georgia (abundant), and many other 

 localities. 



Tijpe.— Cat. No. 62573, TJ.S.N.M. 



SECTION II. INTERZCECIAL AVICULARIA DIFFERENTIATED. 



HINCKSINA MEGAVICULARIA, new species. 



Plate 1, fig. 7. 



Description. — The zoarium incrusts other bryozoa. The zooecia 



are large, distinct, elongated, pyriform, and have a gymnocyst; the 



mural rim is convex, salient, provided with 14 to 20 large hollow 



spines. The opesium is terminal, elliptical, or somewhat pyriform, 



entire; the interzooecial avicularium is large, symmetrical, and has 



a gymnocyst; its opesium is constricted laterally, probably at the 



place where the pivot ought to be. 



,, ^ ^ • fAo=0.30-0.35mm. 



Measurements. — Upesia , „^„ 



^ I /(?= 0.25mm. 



„ . fZs=0.60-0.70mm. 

 2^^^^^{ fe=.0.40mm. 

 Length of avicularia=0.60-0.65mm. 



Affinities. — On account of its large avicularia this species ap- 

 proaches the recent Hlncksina pyrula Hincks, 1881. It differs, 

 nevertheless, in its larger number of spines; unfortunately we are 

 unable to compare the ovicells. 



The specimen figured is very instructive. On a zocecium can be 

 seen the coalescing of opposite spines giving an aspect like the 

 frontal of Membramporella. In other examples many zooecia are re- 

 generated ; in one case a normal zocecium succeeds a normal zocecium 

 and a double row of spines results; in another case an avicularium 

 replaces a zocecium, but in a totally inverted position. 



Occurrence. — Middle Jacksonian (Castle Hayne limestone) ; Wil- 

 mington, North Carolina (very rare). 



Type.—Qai. No. 62574, U.S.N.M. 



OGIVALINA, new genus. 



Endozooecial ovicell. Granular cryptocyst. No dietellae. No 

 spines. 



Genotype. — OgivaXina eximipora^ new species. 



The zooecia have the usual aspect of those in the family Onycho- 

 cellidae, but the interzooecial onychocellarium is replaced by an 

 interopesial avicularium. 



In addition to the genotype this genus is represented by a new 

 species and a new variety froni the Middle Jacksonian of North and 

 South Carolina. 



