NORTH AMERICAN EARLY TERTIARY BRYOZOA. 699 



FIG. 229. Anatomy of tlie family Crisiidae Johnston, 1847. 



A-I. Crisia denticulata Lamarck, 1836. A. Zoarium, natural size. B. Polypide isolated from 

 the tube. (After Milne-Edwards, 1838.) a, tentacles; &, tentacular sheath; c, retractor muscle 

 of the polypide; d, alimentary tube; e, anus. C. Portion of longitudinal section through the 

 polypide. The contour of the cardiac region which has not been covered by the section is repre- 

 sented by stippling. D. Transverse section of a branch of the colony. E. Tentacle, transverse 

 section. F. Strip of a tangential section of the ectocyst. Each of the pores corresponds to a 

 spherular leucocyte. G. Portion of a longitudinal section of the wall of the ovicell. The spheru- 

 lar leucocytes are always abundant in the vicinity of the pores. H. Leucocytes of the^general 

 cavity of a zooecium. (O-H after Calvet, 1900.) coco, stomachic coecum ; cl, interzooecial par- 

 tition; ect, ectocyst; ect', ect", the two cuticular leaves of the ectocyst; em, mesenchyme; ep, 

 endocyst ; cph, epiderm of the pharynx; esf, stomach; ete, external tentacular epithelium; eti, 

 internal tentacular epithelium ; gt, tentacular sheath ; mttpoe, muscular perioesophagial fibers ; 

 mugr, great retractor muscle ; met, anhistous membrane of the tentacles ; oes, oesophagus ; ph, 

 pharynx ; pi/, pylorus ; psp, protospermatoblast morules ; re, rectum ; sm, mesenchymatous lining 

 of the polypide; t, tentacles. I. Section through the inner wall of a zooecium showing the con- 

 nectons from zooecum to zooecum (c) X 330. (After Waters, 1914.) 



J. Crisia. geniculata Milne-Edwards, 1878. Polypide with the tentacles evaginated. (After 

 Milne-Edwards, 1838.) a, tentacles garnished with vibratile cilia; b, stomach; c, intestine; d, 

 anus ; e, retractor muscle of the polypide. 



K. Crisia elongata Milne-Edwards, 1838. Proximal end of zooecium, showing connection (a) 

 to the two neighboring zooecia, through numerous tubes in which there is a septum in the middle 

 of the zooecial walls (w); X 250. (After Waters, 1914.) 



L. Crisidia cornuta Ellis, 1755. Decalcified segment. (After Pergens, 1899.) a. j., link of 

 juncture ; est, stomach ; ep, ectocyst ; p, parenchyme. 



