CORALS AND BRYOZOA. 289 



CLONOPORA, Hall. 1881. 

 Clonopora fasciculata, n. sp. 



PLATE LXVI, FIGS. 1, 2. 



Zoarium simple or ramose, from 1 to 1.50 mm. in diameter. Cell tubes cylin- 

 drical, of nearly uniform size their entire length, diameter about .33 mm.; 

 for two-thirds their length they are sub-parallel, diverging very gradually, 

 then turning abruptly outward, they continue growth at an angle of about 

 forty-five degrees to the axis of the zoarium. On one frond, which is appar- 

 ently well preserved, the cells cease growth on turning outward. 



Formation and locality. Upper Helderberg group, Onondaga Valley, N. Y. 



Clonopora semireducta. 



plate LXVI, FIGS. 3, 4. 

 Clinurpnra semireducta. Hall. Trana. Albany Institute, vol. x, abstract, p. 20. 1881. 



Zoarium ramose, branches generally consisting of an aggregation of cylindrical 

 cell tubes, diameter about 1 mm. ; cell tubes 2.50 in length, diameter .25 mm. ; 

 essentially parallel with the axis of the branch until within about 1 mm. of 

 the aperture, where they turn abruptly outward and continue at nearly right 

 angles to the axis. Most of the specimens consist simply of an aggregation 

 of cell tubes, but some of them have apparently an intercellular substance. 



This species may be distinguished from C fasciculata by its smaller size. 

 Formation and locality. Upper Helderberg group. Falls of the Ohio river. 



Clonopora incurva. 



I'LATK LXVI, FIGS. 8, 6. 

 Clonopora incurta. Hall. Trans. Albany Institute, vol. x, abstract, (). 20. 1881. 



Zoarium about 1.50 mm. in diameter. Length of cell tubes from 3.50 to 4 mm., 

 gradually enlarging to the aperture, where the diameter is about .50 mm. 

 Eight or ten cells commence growth at the same time at the center of the 

 stipe, gradually diverging till within 1.50 mm. from the apertures, when 

 they turn abruptly outward. The apertures are spirally arranged, the group 

 of cells being umbelliforra, the zoarium consisting of a succession of these 

 groups of cells. 

 Formation and locality. Upper Helderberg group, Manlius, N. Y. 



