NO. 5 ORDOVICIAN BRYOZOA — BOARDMAN 25 



Fig. s. Longitudinal view of identified specimen, U.S.N.M. 138270, X 10, show- 

 ing configuration of zooecial walls of the endozone. U.S.N.M. col- 

 lection 2995. 



Plate 3 



Batoslonia implicatum (Nicholson) 



Fig. I. Tangential view of identified specimen, U.S.N.M. 138270, X 50, illus- 

 trating the passage from the thicker walled growth stage to the 

 younger, thin-walled stage. Note variation in diameters of acantho- 

 pores. U.S.N.M. collection 2995. 



Fig. 2. Tangential view of identified specimen, U.S.N.M. 138271, X SO, showing 

 an extreme thickening of zooecial walls and no laminated develop- 

 ment of mesopore walls in a relatively young growth stage. U.S.N.M. 

 collection 2994. 



Fig. 3a. Transverse view of identified specimen, U.S.N.M. 138268, X 10, show- 

 ing transverse shape of zooecia in the endozone and a secondary over- 

 growth incrusting the primary branch. U.S.N.M. collection 2995. 



Fig. 3b. Tangential view from same zoarium, X 50. illustrating an older growth 

 stage characterized by mesopores largely filled with skeletal material. 



Fig. 3c. Longitudinal view from same zoarium, X 50, showing the thin widely 

 spaced diaphragms of the zooecia, the typical notched acanthopore, 

 and the thick, distally curved diaphragms of the mesopores. 



Fig. 4. Longitudinal view of identified specimen, U.S.N.M. 138272, X 50, illus- 

 trating a younger growth stage than that shown in figure 3c. U.S. 

 N.M. collection 2994. 



Plate 3 

 Anaphragma mirabile Ulrich and Bassler 



Fig. I. Longitudinal view of topotype, U.S.N.M. 138273, X 50, showing the 

 progressive broadening of the zone of curved laminae and obscuring 

 of the dark, irregular zooecial boundary as growth proceeded from 

 right to left in figure. Distortion into V-shaped laminae in lower 

 zooecial wall is probably caused by proximity of an acanthopore 

 running along zooecial boundary. U.S.N.M. collection 2996. 



Fig. 2. Longitudinal view of paratype, U.S.N.M. 138274, X 20, displaying ex- 

 tremely thin zooecial walls. U.S.N.M. cotype suite 43218. 



Fig. 3a. Deep tangential section of lectotype, U.S.N.M. 138275, X 50, showing 

 a young growth stage in a zoarium with exceptionally thick zooecial 

 and mesopore walls. Note narrowly amalgamate appearance (dark 

 zones between tubes), and small, almost undistinguishable acantho- 

 pores in a few zooecial corners. U.S.N.M. cotype suite 43218. 



Fig. 3b. Longitudinal section of lectotype, X 20, showing thick zooecial walls 

 and two diaphragms. 



Fig. 3c. Longitudinal section of lectotype, X 50, showing a diaphragm and 

 dark, granular zooecial boundary zone in middle segment of centered 

 zooecial wall. 



Fig. 4. Longitudinal section of branch of topotype zoarium, U.S.N.M. 138276, 

 X 5. showing thin zooecial walls, and general lack of diaphragms. 

 U.S.N.M. collection 2996. 



