NORTH AMERICAN EARLY TERTIARY BRYOZOA. 361 



[Aa=0.12mm. . |Zs=0.20mm. 



Measurements. Aperture, Zooecia ^ _ n n fin, 



lZffl=0.12 mm. \Lz =0.55-0.61) mm. 



Affinities. This species differs from Schizomavella granulifcra and Schizoma- 

 vella elongata in the absence of the median avicularium and in its incrusting 

 zoarium. 



It differs from Ddkaria brevis in its much larger zooecial dimensions. 



It is probable that the. granulations hide very small tremopores. 



Occurrence. Upper Jacksonian (Ocala limestone) : Old Factory, 1| miles 

 above Bainbridge, Georgia (rare). 



Holotype.Crt. No. 64063, U.S.N.M. 



Genus METROPERIELLA Canu and Bassler, 1917. 



1917. Metroperiella CANU and BASSLER, Synopsis of American Early Tertiary Cheilostome 

 Bryozoa, Bulletin 96, United States National Museum, r>. 40. 



The ovicell is hyperstomial and completely surrounds the aperture. The 

 rimule is a large rounded sinus. The frontal is a tremocyst bearing a median 

 avicularium. 



Genotype. Metroperiella (Schisoporella) lepralioides Calvet. 1903. 



Range. Jacksonian-Eecent. 



The known fossil species of the genus are: 



Metroperiella (Lepralia) trigonostoma Reuss, 1847. 



Metroperiella (SchizoporeUa) lata MacGillivray, 1882. 



There are some avicularian zooecia with a large mandible in all the species 

 of this genus. 



METROPERIELLA (?) ALBORA, new species. 



Plate 47, figs. 1, 2. 



Description. The zoarium is unilamellar. The zooecia are elongated, distinct. 

 nearly cylindrical; the frontal is a tremocyst with irregular pores, and is very 

 little convex. The aperture is oval; the rimule is semielliptical, very wide and 

 separated from the anter solely by two lateral denticles on which the transverse 

 axis of the operculum is inserted ; a wide, white, improminent peristome surrounds 

 the aperture. The median avicularium is small, little salient, elliptical, the beak 

 turned toward the bottom. 



f/<a=0.15mm. 



. 

 ' cia 7^0.35-0.40 mm. 



Affinities. The frontal tremocyst reposes on a very thin and finely perforated 

 olocyst. The tremopores are very short tubules with their section visible on the 

 olocyst. Around each aperture there are four large tremopores: two placed on the 

 distal zooecia and each of the two others on adjacent zooecia. 



This species differs from Metroperiella (irandipora in its much narrower 

 zooecia (0. 35 mm. instead of 0.45 mm.), its wide white peristome and the four 

 large pores around the peristome. 



