172 PALEONTOLOGY OF NEW YORK. 



irregular, transverse elevations, nine in the space of 5 mm., which, though 

 prominent, do not obscure the branches. Fenestrules oval, length about 

 .38 mm., width .25 mm. 



The celluliferous face of this species has not been observed, but the species 

 may easily be distinguished from any other at present known by the smaller 

 branches, dissepiments and fenestrules, and the much more compact appearance 

 of the frond. 



Formation and locality. Upper Helderberg group, Walpole, Ontario, Canada. 



PTILOPORINA, s. G., Hall. 1885. 

 Fenestella (Ptiloporina) conica, n. sp. 



PLATE XLm, FIGS. 2-4. 



Brvozoum infundibuliform, rapidly expanding, composed of primary and second- 

 ary branches. The primary branches are very frequent, strongly elevated 

 above the others, width .50 mm. ; secondary branches about .30 mm. wide, 

 all angular and slightly carinated. On one side of a frond, for some distance 

 above the base, all the branches are large and directly connected by dissepi- 

 ments. Interstices wider than the primary branches. Dissepiments very 

 slender, width .20 mm., angular, slightly carinated, much depressed, three or 

 four in the space of 5 mm. Fenestrules sub-quadrangular, length 1 to 1.25 

 mm., width .35 to .50 mm. Cell apertures in two or three ranges, sixteen in 

 the space of 5 mm. 



This species can be distinguished from the others of this sub-genus, by the 

 numerous primary branches, slender dissepiments and large fenestrules. 

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



Fenestella (Ptiloporina) pinnata, n. sp. 



PLATE XLin, FIGS. 6, 8. 



Bryozoum infundibuliform, composed of primary and secondary branches. Pri- 

 mary branches distant, width .50 mm., widthof secondary branches .35 or .40 

 mm., all angular and slightly carinated. Interstices wider than the branches. 



