70 PALEONTOLOGY OF NEW YORK. 



ally diverging until near the surface, when they abruptly turn outward; 

 septa infrequent. Cell apertures oval, length about .22 mm., width from 

 one-half to two-thirds the length ; closely and irregularly disposed. Inter- 

 apertural space spinulose. The branches, when in a perfect condition, .ire 

 covertnl by closely arranged aculeate processes. Many of the branches are 

 annulated, but this feature is not constant. 



In some varieties this species resembles Trematopora (TVematella) annulata, but 

 may be distinguished by the oval cell apertures. 



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



Tbematopoba (Tbematella) glomebata. 



PLATE XXV, KIQ8. I, 6. 



Tretnatella glomerata. Hall. Report of State Geologiat for 1885, advance sheets. Expl. pi. 25, figs. 4, 5. 



1886. 



ZoABiDM ramose, solid; branches from 1.50 to 2 mm. in diameter; bifurcations 

 frequent. Cells tubular, in contact for the greater portion of their length, 

 slightly diverging as they approach the surface ; septa infrequent or want- 

 ing. Intercellular space apparently solid. Cell apertures usually oval or 

 circular, length .30 mm. ; closely and irregularly disposed. Interapertural 

 area elevated, angular or nodulose. Pseudopores variable in number on 

 different portions of the frond, generally infrequent. 



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

 Tbematopoba (Obtuopoba) scutulata. 



PLATE XXVI, FIGS. 7, 8. 



Treinatoptrra xcutuUUa, U&ll. Trans. Albany Institute, vol. x, abstract, p. 6. 1S81. 



" " " Rejwrt of State Geologist for 1882. Expl. pi. 24, figs. 7, 8. 1883. 



Zoabium ramose, solid; branches widely diverging, 1 mm. in diameter; bifur- 

 cations frequent. Cell apertures oval, length .25 mm., width .18 mm. ; dis- 

 posed in longitudinal parallel rows, alternating, forming oblique transverse 

 rows, the latter arrangement being the most conspicuous : peristomes thin, 

 inclosing a rhomboidal area, with a minute spinule at etich angle. 



