EARLY TERTIARY CHEILOSTOME BRYOZOA. 73 



base 2 cm. 5 mm. in width. The zooecia are disposed in two groups, 

 back to back and inseparable. The axial zocecia back to back are 

 oriented; all the other zooecia are cumulate. The superficial zooecia 

 are distinct, urceolate, little raised, very oblique ; the frontal is quite 

 convex, smooth, bearing 0-3 improminent avicularia with pivot ; the 

 frontal is formed of a very thick olocyst. The apertura is oval, 

 deeply imbedded at the base of a peristomie; the peristomice is ir- 

 regular, suborbicular. The deep zooecia haA^e a flat frontal; their 

 avicularia are prominent between the superficial zooecia. The inter- 

 zoa'cial avicularia are distinct, elliptical, of the size of zooecia; 

 they have a pivot; their orifice is like the beak of a duck; the pas- 

 sage of the reflexor muscles of the operculum is indicated by the very 

 small perforations on the inferior cavity ; the beak is salient above the 

 zoarium. The incomplete zooecia are quite numerous. On many 

 zoaria there are some distinct groups of large zooecia and of small 

 zooecia. 



(ha=0.1i) mm. 

 Measure7nents. — Apertura (interior) j ^^^ _q -j^^j ^^^^^^ 



fZs=0.60mm. 

 Zocecia j^^ =0.30-0.35 mm. 



Variations. — Following the rule, the variations of these Cellepores 

 are quite great, but the species is always rather easy to determine by 

 its zoarial size. 



Occurrence. — Lower Jacksonian: Jackson, Mississij^pi (common). 



Middle Jacksonian: "Wilmington, North Carolina (common); 3^ 

 miles south of Perry, Georgia (common). 



Upper Jacksonian: Cocoa post office, Choctaw County, Alabama 

 (very common). 



Vicksburgian : 7| miles from Bladen vSprings, Alabama (rare); 

 Bed Bluff, Wayne County, Mississippi (rare). 



Type.—Q2it. No. 62613,' U.S.N.M. 



Family CONESCHARELLINIDAE Levinsen, 1909. 



The zocecia are erect; the apertura is terminal. The gemmation 

 is always and uniquely lateral. The ovicell is hyperstomial and 

 recumbent. There is a zooecial and a zoarial hydrostatic system. 



This is a very mysterious group A^Iiich has given the zoologists 

 much trouble. Only Maplestone in 1910 ^ has given some details 

 on the zoarial life. 



Almost all our specimens belong to a new American genus 

 Schizorthosecos. 



' 1910. Maplestone. On the Growth and Habits of Biporae, Proceedings Royal Society 

 Victoria, vol. 23. 



