CORALS AND BRYOZOA. 277 



Formation and localities. Hamilton group, Hopeton, shore of Seneca lake, 

 Yates county, and in the Genesee Valley, Livingston county, N. Y. 



HE DE EEL LA, Hall. 1881. 

 Hedeeella cirrhosa. 



PLATE LXV, FIGS. 12, 13. 



BedereUa cirrhosa. Hall. Trans. Albany Institute, vol. x, p. 194. 1881. 

 Report of State Geologist for 1883, p. 53. 1S84. 



ZoARiDM consisting of a filiform, tubular axis, from which proceed laterally 

 simple tubular cells, and at irregular intervals other tublues having the same 

 manner of growth as the main axis ; parasitic, procumbent, attached for 

 its entire length, occurring on Cyathophylloid corals, Brachiopoda and 

 Crinoid columns. Cells about 1 mm. in length ; diameter .20 mm. ; trans- 

 verse section nearly circular, turning abruptly outward at the extremity, the 

 aperture being parallel with the axis of the branch and circular, generally 

 alternating, distant on the same side of the branch from 2 to 2.50 mm., 

 though sometimes occurring at irregular intervals. Surface marked by 

 transverse striae and angular annulations. 



This species may be easily distinguished from others of this genus by its 

 much more slender, filiform character. 



Formalim and locality. Hamilton group, York, Livingston county, N. Y. 



Hedeeella Canadensis. 



Pi:4ATK LXV, FIGS. 1-8, U and 18? 



Alectol Canadensit, Nicholson. Canailian Naturalist, vol. vii. No. 3. 1874. 

 AiUoporat Canadensis, Nicholsoit. Pal. Prov. of Ontario. 1874.' 

 Hederella " Hall. Trans. Albany Institute, vol. x, p, 194. 1881. 



Report of State Geologist for 1883, p. ,53. 1884. 



ZoARiOM parasitic, procumbent, attached for its entire length ; usually occurring 

 on Corals or Brachiopoda, most frequently on Heliophyllum Haiti. It consists 

 of a primary cylindrical, tubular axis, which has lateral tubular cells at fre- 

 quent intervals, and occasionally cells having the same manner of growth as 

 the primary axis. This mode of growth is indefinitely continued so that large 



