CORALS AND BRYOZOA. 173 



Dissepiments slender, width .25 mm., rounded, sometimes slightly carinated, 

 depressed below the plane of the branches, four in the space of 5 mm. Fen- 

 estrules broadly oval, somewhat variable in size, length usually about 1 mm., 

 width from .35 to .50 mm. 



Celluliferous face not observed. 



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

 comparatively wide interstices, and the size of the secondary branches ; also by 

 their great divergence, which gives to each primary branch, with its lateral 

 secondary branches from it, a pinnate appearance. 



Formation and locally. Upper Helderberg group, Schoharie, Schoharie county, 



N. Y. 



Fenestella (Ptiloporina) disparilis, n. sp. 



PLATE XLm, FIGS. 7. 8. 



Bryozoum infundibuliform, of coarse appearance, composed of primary and 

 secondary branches ; primary branches .70 mm. wide ; the secondary ones .40 

 mm., increasing to .50 mm., probably on larger fronds some of the secondary 

 branches would increase to .70 mm.; secondary branches straight; primary 

 branches sinuous, all angular, slightly carinated, the primary branches elevated 

 about .40 mm. above the others. Interstices of the same width or wider 

 than the secondary branches. Dissepiments slender, width .25 mm., angular, 

 slightly carinated, depressed below the plane of the branches, about five in 

 the space of 5 mm. Fenestrules oval, length .75 mm., width .40 mm. 



On the celluliferous face the dissepiments are rounded, much depressed. 

 Fenestrules of the same appearance as on the opposite face. Cell apertures 

 of the primary bnanches in from three to five ranges, those of the secondary 

 branches in from two to three ranges, opening outward and laterally, eigh- 

 teen in the space of 5 mm., closely disposed. 



On the celluliferous face this species may be distinguished from F. (Ptilo- 

 porella) laticrescens by the stronger branches and larger fenestrules, the sinuous 

 character of the primary branches and less frequent dissepiments, the number 

 of branches being nearly the same. 



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



