CORALS AND BRYOZOA. 177 



vated, angular or rounded, forming polygonal areas inclosing the cell aper- 

 tures, length about .45 mm., width one-half the length. There are compara- 

 tively prominent, conical nodes at the angles of the elevations ; when the 

 frond is well preserved the elevations are rounded and strongly granulose ; 

 when a little worn or macerated they are acutely angular and the granules 

 are minute. 



This species has a general resemblance to T. (0.) suhquadrata and T. (O.) 

 hexagona ; from the former it is distinguished by the stronger branches, the 

 larger cell apertures and the larger and more elongate vestibular areas ; from 

 the latter by the somewhat larger cell apertures and vestibular areas, and by 

 the more prominent nodes at the angles of the elevations, and the smaller 

 granules : from T. (O.) nexa it is distinguished by its larger cell apertures and 

 much stronger angular elevations between them, and their more irregular 

 disposition. 



Formation and hcalitij. Hamilton group, West Hamburg, Erie county, N. Y. 



Trematopora (Orthopora) scbquaurata. 



PLATE LV, FIG. 10; ANU PLATE LVI, FIGS. 1,6. 



Trnnatopora tuhqvadTota, Hall. Ti-ans. Albany Institute, vol. x, p. 181. 1881. 

 " •' " Report of SUte Geologist for 1>83, p. 11. 1884. 



ZoARiUM ramose, solid ; bifurcations infrequent ; branches widely diverging, 

 diameter about 1.25 mm. Cells tubular, arising from the center of the 

 branch, length a little less than 1.50 mm., for the greater portion of their 

 length oblique, straight, curving outward near the surface, in contact for 

 nearly their entire length, slightly separating as they approach the surface ; 

 cell walls apparently corrugated ; septa very thin and infrequent. Cell aper- 

 tures oval, length about .18 mm., width one-half the length, very closely and 

 sometimes irregularly disposed, but usually in longitudinal, parallel rows, 

 alternating and forming oblique transverse rows, having an angle of about 

 forty-five degrees to the axis of the branch, the latter arrangement the most 

 conspicuous. Peristomes obsolete. The narrow space between the cell 

 apertures is elevated, sharply angular, enclosing the apertures in a rhomboidal. 



