NORTH AMERICAN EARLY TERTIARY BRYOZOA. 



507 



L '25 N 



FIG. 143. Genus Schixellozoon Canu and Bassler, 1917. 



A-D. Scliiscllozoon solandcria Risso, 1826. A. Portion of u colony at the point of bifurc.i- 

 tiun showing the frontal structure of the adult zooecia and of the ovicells, X 25 (sp=pseudo spi- 

 ramen). B, C. Ojierculum, X CO; seen normally and in profile. D. Mandible of a frontal avi- 

 culariurn, X 120. (A-D after Calvet, 1902.) 



E-L. SchiseUoxoon imperati Busk, 1884. E. Zooecia provided with a pseudo-spiramen, X 25. 

 F. Frontal avicularium, X 25. G. Ovicell, X 25. H, I. Operculum, X 85. (After Waters. 1S58.) 

 J. Mandible of a small frontal avicularium, X 85. K. Mandible of a large frontal avicularium. 

 L. Posterior side of a zoarium, X 25. (K-H, .T-I. after Busk, 1884.) 



M. Schisellozoon tessellatum Hincks, 1878. Group of opercula and mandibles. (After 

 Busk, 1S84.) 



N. ScMzelloznon clongatum Busk, 1S84. Opereula and mandible. (After Busk. 1884.) 



