NORTH AMERICAN EARLY TERTIARY BRYOZOA. 115 



DIVISION H. WITH INTERZOOECIAL AVICULARIA DIFFERENTIATED. 



The species of this section are MS beautiful as they are well characterized. Then 

 avicularia when present are similar in every respect to those of the recent species, 

 such as Hincksina pyrtrta, H. flustroirfes, H. scelctos, etc., of which we have figured 

 the mandibles. They are, however, without a pivot. One must not confound the 

 species of this genus with those of the genus Ornatella Canu. 1900, in which the 

 ovicells are hyperstomial. 



HINCKSINA ELEGANS, new species. 



Plate SO. figs. 12-15. 



Description. The zoarium is unilamellate. creeping over algae. The zooecia 

 are elongate, distinct, elliptical, provided with a gymnocyst: the mural rim is 

 thicker in the proximal part below, finely granulated, adorned on its summit with a 

 crown of large granules or of hollow spines: the two distal spines are larger, con- 

 stant, and symmetrical. The opesium is elliptical and entire. The ovicell is a 

 small distal convexity, smooth and indistinct: the border of the opesium is thick in 

 the ovicelled zooecia. 



[0=0.32-0.37 mm. 



-ir , ,". \nu ir.oa u.o I mm. n 



Measurements. Opesia Zooecia 



1/0=0.18-0.20 mm. 



2=0.45-0.47 mm. 

 fe=0.32-0.35 mm. 



Affinities. Of this elegant species we possess unfortunately only the three 

 figured specimens. The adornment of its mural rim is a small masterpiece of sculp- 

 turing which could well serve as model for the decorator. The little granules must 

 be the traces of small hollow spines attenuated in the process of fossilization. The 

 zooecia with ovicells have also the aspect of regenerated zooecia. It may be. there- 

 fore, that the female polypide succeeds the male in total regeneration. 



This species differs from H!ii<-l,'xin<i mxtulifera in the presence of its two distal 

 spines, which are larger than the areal spines, and in the opesial thickening of the 

 ovicelled zooecia. 



Occurrence. Vicksburgian ("Chimney rock" of Marianna limestone) : 1 mile 

 north of Monroeville, Alabama (very rare). 



Cotypes.Cnt. No. 64232, U.S.X.M. 



HINCKSINA PARVAVICULARIA. new species. 



Plate 22, figs. 14. 15. 



Description. The zoarium is inerusting shells. The zooecia are large, elon- 

 gated, distinct, pyriform or elliptical, with or without gymnoryst : the mural rim i-. 

 prominent, convex, ornamented with sixteen large hollow spines. The opesium is 

 elliptical, entire. The interzooecial avicularium is relatively xnmll and nnsvm- 

 nietrical. 



-,, . f&0=0.40-0.4o mm. . |7L2 = 0.<;i> n.7n nun. 



Measurements. Opesia, _. Zooecia, 



l>=0.25-0.30 mm. 0.40-0.45 mm. 



Avicularia =0.33 0.45 mm. 



Affinities. This species differs from r/!in-/.-xiii<t fin.*! roitli x Ilinrks. Issi'i. in its 

 larger spines, its thicker mural rim. and it- !<>- -vmmri rii-al avic-ularia. The 



