Plate IV. 



Conularia gracilis, Hall, Utica slate, Dolgeville, N. Y. 

 Figure 1. Group of young. Natural size. 

 Figure 2. Group of young. Natural size. 



Figure 3. Young attached to a small projection. Natural size. 



Figures 4 to 35. Various growth stages, x 4. 



Figure 36. Uncompressed specimen. x4. 



Figure 37. Slightly compressed specimen. x4. 



Figure 38. Uncompressed specimen. x4. 



Figure 39. Specimen terminated by septum. Natural size. 



Figure 40. Type of Sphenothallus angustifolius, Hall, Canajoharie. N. Y. Natural size, a, young 

 specimens attached; b, natural section, showing the composition of the pyramid of four faces. 



738 



