NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
361 
Measurements. — Aperture 
J A<z=0.12 mm. 
1 7a=0.12 mm. 
Zooecia 
Zs= 0.20 mm. 
Zs=0.55-0.60 mm. 
Affinities. — This species differs from Schizomavella granulifera and Schisoma- 
vella elongata in the absence of the median avicularium and in its incrusting 
zoarium. 
It differs from Daharia brevis in its much larger zooecial dimensions. 
It is probable that the granulations hide very small tremopores. 
Occurrence. — Upper Jacksonian (Ocala limestone) : Old Factory, 14 miles 
above Bainbridge, Georgia (rare). 
Holotype.— Cat. 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, p. 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. — M etroperiella (Schizoporella) lepralioides Calvet, 1903. 
Range. — J acksonian-Recent. 
The known fossil species of the genus are : 
M etroperiella ( Lepralia ) trigonostoma Eeuss, 1847. 
M etroperiella (Schizoporella) 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 Avide, white , improminent peristome surrounds 
the aperture. The median avicularium is small, little salient, elliptical, the beak 
turned toward the bottom. 
M easuremem ts. — Aperture 
[ ha=0. 15 mm. 
\7a=0.15 mm. 
Zooecia 
7,2=0.75 mm. 
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 Ausible 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 grandipova. in its much narroAver 
zooecia (0. 35 mm. instead of 0.45 mm.), its wide white peristome and the four 
large pores around the peristome. 
