6 
PALEONTOLOGY OF NEW YORK. 
Vermtpora robusta. 
PLATE II, PIGS. 32, 33. 
Vermipora robusta . Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 144. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 8, figs. 82, 33. 1883. 
Corallum ramose; diameter of branch 7 111 m. Exposed portion of the cell- 
tubes from 6 to 8 mm. in length; diameter at the aperture 2 mm. Surface 
marked by obscure transverse strias and undulations. 
This species differs from V. serpuloides in its much larger size and compara¬ 
tively shorter cells. 
Formation and locality. Lower Helderberg group, Schoharie, N. Y. 
Vermipora? tortuosa. 
PLATE II, FIG. 23. 
Vermipora? tortuosa.. Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 144. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 2, fig. 23. 1883. 
Corallum consisting of an aggregation of elongate, sub-cylindrical tubes, 
increasing by lateral gemmation. Length of cell tube 4 mm.; diameter 
at the aperture .50 mm. Surface marked by numerous oblique transverse 
annulations which give to the cell tubes a twisted appearance. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
STRI ATOPOIt A, Hall. 1852. 
Striatopora Issa. 
PLATE III, FIGS. 14, 15. 
Striatopora Issa , Hall. Twenty-sixth Rept. N. Y. State Mus. Nat. Hist., p. 114. 1874. 
“ “ “ Thirty-second Rept. N. Y.^State Mus. Nat. Hist., p. 144 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 3, figs. 14, 15. 1883. 
Corallum ramose; diameter of the branches reaching 10 mm.; composed of 
thick-walled, tubular cells, arising from the center of the branch, rapidly 
increasing in size and quite abruptly curving to the surface; cell tubes 
polygonal, from four to six-sided ; unequal in size through the frequent inter¬ 
calation of young cells; diameter at the surface from 1 to 2 mm.; interior 
