356 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



much of the aperture (fig. 7); it is therefore always closed by the operculum; 

 meanwhile the orifice of the aperture persists in the interior (fig. 8) ; we have come 

 to the conclusion that the operculum is lowered to allow the escape of the larvae. 



The tangential section (fig. 12) reveals clearly a tremocyst surmounting an 

 olocyst closely united with it; the tremopores are very small and wide open. In 

 the interior (fig. 11) the olocyst appears absolutely smooth, but when greatly 

 magnified it is easy to distinguish the small pores corresponding to the tremopores. 



Affinities. This species differs from Dakaria laxata in its bilamellar zoarium 

 and its smaller zooecial width, always less than 0.50 mm. instead of 0.60 mm. It 

 differs from SchizomaveMa elongata in its lesser zooecial length, which is 0.70 mm. 

 instead of 1.00 mm. 



Occurrence. Middle Jacksonian: Baldock, Barnwell County, South Carolina 

 (very common) ; 12 miles southeast of Marshallville. Georgia (rare) ; 3} miles south 

 of Perry, Georgia (rare) ; Rich Hill, Georgia (rare) ; 5^ miles southeast of Knox- 

 ville, Georgia (rare) ; 18 miles east of Wrightsville, Georgia (rare) ; \ mile south- 

 east of Georgia Kaolin Company Mine, Twiggs County, Georgia (rare) ; 3 miles 

 north of Grovania, Georgia (rare) ; Wilmington, North Carolina (rare). 



Upper Jacksonian (Ocala limestone) : Chipola River, east of Marianna, Jackson 

 County, Florida (common). 



Cotypes.C?A. No. 64058, U.S.N.M. 



SCHIZOMAVELLA GRANULOSA, new species. 



Plate 46, figs. 13-16. 



Description. The zoarium incrusts bryozoa. The zooecia are elongated, dis- 

 tinct, fusiform; the frontal is little convex and formed of a granular tremocyst 

 with very small pores. The aperture is formed of a semilunar anter and of a 

 wide rounded rimule, separated by two inner condyles. The ovicell is Very large, 

 salient, formed of a large area surrounded by a small, salient collar; it entirely 

 surrounds the aperture, but without forming a peristomie. The median avicu- 

 larium is quite small, little prominent in the immediate vicinity of the aperture. 



/i=0.10 mm. ILs=O.GOmm. 



' cla U= .40mm. 



Affinities. The granular frontal is characteristic of this species; it resembles 

 strangely in its granulations, in its bordered ovicell, and in its avicularium, placed 

 near the aperture, the recent Schizoporella marsupifera Busk, 1884. It differs from 

 the latter only in its more elongated zooecia and its nontransverse aperture. 



We have observed (fig. 15) a regenerated avicularian zooecium in the interior 

 of a primitive zooecium, where another one has succeeded it with a very small 



mandible. 



Occurrence. Upper Jacksonian (Ocala limestone) : Old Factory, H miles 



above Bainbridge, Georgia (rare). 



Cotypes.Czt. No. 64059, U.S.N.M. 



