PtATE 45. 



Figs. 1-9. Sclii::oiioOiell(i riinincn I.ons<l:ili'. 1S45 (p. :-!42). 



1. Three fragments of tlie bilaiuellar zoarium. natural size. The third specimen shows 



a lateral frond growing at right angles to the original one. 



2. Surface of zooecia, with thickened frontal. X 20. in which tlie oral sinus has 



disappeared. 



3. A zoarium sliowing the nsu.-il aspect of the zooecia. X 2i). Tlie rimule and avicularia 



directed outward are shown. 

 4, 5. Two surfaces of ovicell liearing zooecia. X 20. The ovicells are smooth. 



6. A tangential thin section, X 100, including an nvicnlarium. 



7. Slietch of longitudinal section. X TO. through a zooecium with ovicell. 



a I), apertura : or or, orifice of ovicell: or. ovicell; s, septula; tr, tremocyst; g, 

 zooecium. 



8. View of the interior, X 20. The oral sinus is well marlied and the avicularia are 



present. 



9. Tangential tliin section of a zooecium. X 100. showing microstructure of the 



tremocyst. 

 Middle Jacksouian (Castle Hayne limestone) : Wilniiugtou. North Carolina. 

 Cat. No. 040.51. U.S.N.M. 

 Figs. 10-lS. ^c-hizopoOrcUa Unea Lon.sdale, 184.o (p. 340). 



10. Two fragments of the bifoliate zoarium, natural size. 



11. Portion of a zoarium, X 20, showing the structure of the ovicells. 



12. Narrow zooecia without ovicells. X 20. 



13. Wide zooecia, X 20. 



14. Surface of zooecia without ovicells, X 20. The separating thread is well developed. 

 lo. Portion of a zoarium, X 20, with ovicelled zooecia. 



10. Tangential thin section through the frontal. X 20. illustrating structure of the 



tremocyst. 

 IT. Mew of the interior, X 20. sliowiug the perforated oloeyst. 



15. Sketch of vertical section. X 20, passing through two ovicelled zooecia. 

 Middle Jacksonlan (Castle Hayne limestone) : Wilmington. North Carolina. 



Cat. No. 64052. U. S. N. JI. 

 40 



