152 Thirty-second Report on the State Museum. 



•» 

 Trematopoka parallela, n. sp. 



(PLATE XI, FIGS. 13, 14.) 



Bryozoum ramose, solid ; diameter of branches about one mm. ; cell-aper- 

 tures oval, .30 mm. in length, closely arranged in parallel, longitudinal and 

 oblique transverse rows ; margins elevated, ornamented with four or five minute 

 spinules. 



This species differs from T. regularis in its larger cell-apertures, which are 

 more closely arranged, and is without the longitudinal ridge dividing the rows 

 of apertures. 



Formation and locality. Lower Helderberg Group, near Clarksville, N. Y. 



Trematopora rhombipera. 



(PLATE XI, FIGS. 15-20.) 



Trematopora rliombifera, Hall. Twenty-sixth Rep. N. Y. State Mus. Nat. Hist., 



p. 103. 1874. 



Bryozoum ramose, solid ; diameter of branches from one-half of one mm. 

 to two mm. ; cell-tubes arising from the centre of the branch and quite abruptly 

 curving to the surface ; cell-apertures oval or rhomboidal, numerous, contiguous ; 

 eighteen in the space of five mm. longitudinally, and twenty-four in the same 

 space transversely ; arranged spirally around the branch in quincunx order ; cell- 

 walls thin, but frequently thickened by silicification ; in well-preserved speci- 

 mens serrated on their edges. 



Formation and localities. Lower Helderberg group, near Clarksville, and 

 at Schoharie, N. Y. 



Trematopora crassa, n. sp. 



(PLATE XI, FIGS. 21, 22.) 



Bryozoum forming irregular expansions or hollow branches ; cells .25 mm. 

 in diameter, circular, irregularly and closely arranged ; margins of apertures 

 thin, but slightly elevated ; surface marked by frequent maculae, which are des- 

 titute of cells. 



Formation and locality. Lower Helderberg group, Schoharie, N. Y. 



CALLOPORA, Hall. 

 Callopora macropora. 



(PLATE XI, FIGS. 23-29.) 



Callopora macropora. Hall. Twenty-sixth Rep. N. Y. State Mus. Nat. Hist., 



p. 100. 1874. 



Bryozoum ramose, solid, slender, from one to two mm. in diameter ; branches 

 comparatively infrequent, widely diverging ; cell-apertures elongate, oval, or 

 polygonal, variable in size, margins elevated, intercellular spaces narrow ; 

 frequently the cells are contiguous, intercellular pits small, angular ; generally 

 only a single range ; cell-margins frequently spinulose at the angle. 



