X011TII A.MKKK'AX KARLY TERTIARY BRYOZOA. 171 



-itefit.In its sin;i]] micrometrie dimensions this species dearly . litters 

 from the others. It is rather dose to st,nii<-iit>f<11,i // rin'/rii/ifcrif, whose opesium 

 is often pyriform; it is distinguished from it by the very peculiar disposition of 

 its cryptocyst, which is developed laterally and inferiority to the opesium. 



Occurrence. Lower Jaeksonian i Moodys marl): Jackson, Mississippi (com- 

 mon). 



retypes Cut. Xo. 63938, T.S.X.M. 



STAMENOCELLA MEDIA VICULIFERA Canu and Bassler, 1917. 



Phi re 31, figs. 1-5. 

 1917. StiiincnorriiH -mnHii rii/if<ni CANT and BASSLER, Synopsis of American Early 



Tertiary Cueilostome Hi-y.-xon. Bulletin 96, United States National Museum, p. 22, 

 pi. 3, fisr. 1. 



Description. The zoarium is bilamellar, with the two lamellae back to back 

 and inseparable. The zooecia are very elongated, narrowed behind, distinct or 

 indistinct; the mural rim is thin, salient, somewhat enlarged and attenuated, 

 rounded, smooth. The opesium is elliptical or oval, entire; the gymnocyst is flat 

 or somewhat convex and nearly as long as the opesinm. The avicularium is salient 

 and placed in the middle of the gymnocyst. The ovicell is rarely intact. 



. (7*0=0.40 mm. . .3=0.80 mm. 



Mea 8U re m ents.-0^^ lo=0 - 1Q mm Zooecia fo=0>20 _ 04 mill . 



Variations and affinities. This species apparently lived in agitated waters. 

 Although widely distributed, it is often very rare, and specimens are always more 

 or less worn. In this condition the mural rim is worn away and invisible, the 

 zooecia indistinct, and the avicularia absent or replaced by a concave cicatrix 

 (fig. -2). We have never found the ovicell intact; it is always more or less broken, 

 but its place is clearly visible on the gymnocyst, notably in the specimens from near 

 Perry, Georgia (fig. 3). The avicularium is of the simple type without denticles 

 or pivot. The dimensions in this species are much smaller than in /S. r/randis, and 

 it is rarely as well preserved. On certain specimens from Rich Hill, Georgia, we 

 have observed sometimes four punetations at the base of the gymnocyst. The rare 

 -pedmens from the Vicksbnrgian are very mediocre in preservation and have the 

 abraded aspect shown in figure 5. 



Occurrence. Middle Jaeksonian : Rich Hill, Crawford County, Georgia (very 

 common ) ; 3^ miles south of Perry. Georgia (very common} ; 18 miles west of 

 Wrightsville, Johnson County, Georgia ( rare) ; 3 miles north of Grovania, Georgia 

 (rare) : 12 miles southeast of Marshallville. Georgia (rare) ; 17 miles northeast of 

 Hawkinsville, Georgia (rare) : one-half mile southeast of Georgia Kaolin Company 

 Mine. Twiggs County, Georgia (rafei : Baldock, Barnwell County, South Carolina 

 (rare) : Wilmington. Xorth Carolina i rare). 



Vicksbnrgian (Marianna lime-tone) : Salt Mountain. "> miles .south of Jackson, 

 Mi issippi (doubtful) ; near Claiborne. Monroe County. Alabama (doubtful). 



Coty'pes.C&t. Xos. r.:>:>Sl. r,:i;i:;:t. i;:','.UO. TJ.S.N.M. 



