NORTH AMERICAN EARLY TERTIARY BRYOZOA. 449 



LEIOSELLA ROSTRIKERA Canu and Bassler. 1917. 



Plate 92, tigs. 11-17. 



1017. Lciosel/a rust rif era CANU and BASSLER, Synopsis American Early Tertiary Cueilo- 

 storne Bryozoa, Bulletin 96, United States National Museum, p. 48, pi. 5, fig. 1. 



Description. The zoarium is free, bilamellar; the fronds are narrow, flat, 

 claviform, bifurcated. The zooecia are elongated, distinct, ovoid; the frontal is 

 smooth, convex, formed by a thick olocyst. The peristomice is irregular; the 

 rimule-spiramen is bordered laterally by the oral avicularium. The aperturu is 

 elongated, ovoid, very oblique. The oral avicularium is large, transverse, salient, 

 with the beak strong and curved ; it is provided with a pivot and a large mandible, 

 more or less spatulate. On the frontal, there are two small, elliptical aviculariu 

 with round mandible. 



,, -p t \/ipe=0.30mm. Apertura jAa=0.11 mm. 



Measurements. Peristomice ,5 



I lpe=0.25 mm. (interior) l7a=0.10 mm. 



ZooeciaJZ s =0.90-1.00 mm. 

 ( interior) 1/3=0.25-0.30 mm. 



Variations. At the exterior the measurements are quite variable because of 

 irregularity in calcification and the unequal development of the avicularium. The 

 apertura is very oblique and elongated; in perspective in the interior (fig. 16) it 

 appears transverse and elliptical. The oral avicularium on account of its great 

 prominence is very fragile and easily broken (fig. 13) ; it is more or less lost in the 

 thickness of the olocyst (figs. 14, 15). The small frontal avicularia are not always 

 visible (fig. 15). 



Occurrence. Vicksburgian ("Chimney rock" of Marianna limestone): One 

 mile north of Monroeville, Alabama (very common). 



Vicksburgian (Eed Bluff clay) : Seven and one-half miles southeast of Blaclen 

 Springs, Alabama (common). 



Cotypes. Cat. No. 62597, U.S.N.M. 



LEIOSELLA GRANDISORA, new species. 



Plate 92, fig. IS. 



Description. The zoarium is free, subcylindrical. The zooecia are indistinct, 

 somewhat elongated ; the frontal is small, hardly convex, and is formed of a thick 

 olocyst. The peristomice is very large, funnel-shaped, provided with a large 

 rimule-spiramen, little distinct; the apertura is large, elongated, somewhat oval. 

 The ovicell is large, prominent, transverse ; the peristomice of the ovicelled zooecia 

 is elliptical and transverse. In the peristomie there is a large thin, triangular 

 avicularium. 



Measurements. Peristomice J hpe= 0.40-0.45 mm. Apertura J ha=0.30 mm. 



(exterior) Upe=0.30mm. (interior) lZa= 0.25 mm. 



. JZs=0.70mm. 

 Zooecia 7 



(73=0.40-0.45 mm. 



5589920 Bull. 106 29 



