CORALS AND BRYOZOA. 269 



This species is very characteristic and can be easily distinguished from any 

 other at present known, in this horizon, by the peculiar manner of growth. 

 A fragment of a branch, where the base is not preserved, somewhat resembles 

 Stidopora subcarinata, but the branches are wider, the ridges separating the rows 

 of apertures are stronger, the central ridge is much more conspicuous, the 

 marginal cell apertures are smaller and the marginal non-celluliferous space is 

 narrower. 



Formation and localities. Hamilton group. Black Point, Canandaigua lake ; 

 Bellona, Yates county ; Lodi Landing, Seneca Lake, and Darien Centre, Genesee 

 county, N. Y. 



Stictoporina, nov. sub. gen. 

 Stictopora (Stictoporina) claviformis. 



KOT FIGUBBD. 



Trtmatopora clavlfonnis. Hall. Trans. Albany Institute, vol x, p. 181. 1881. 

 " " " Report of State Geologist foi- 1883, p. 12. 1884. 



ZoARiUM consisting of an erect frond of 8 to 10 mm. in height ; base obtusely 

 pointed, and for a short distance above the frond is cylindrical, diameter about 

 .80 mm., gradually enlarging and becoming flattened ; width above a bifurca- 

 tion a little more than 1 mm., increasing to 2 mm. ; no non-cclluliferous 

 mfirginal space ; transverse section broadly lenticular or flattened oval, greatest 

 thickness observed about .80 mm. The first bifurcation occurs at 5 mm. 

 above the base, the others at intervals of 3 mm. ; on the specimens observed 

 there are not more than three bifurcations, and this number occurs on one 

 specimen only. Cells tubular, arising obliquely from amesotheca. Cell aper- 

 tures oval, length about .25 mm., width two-thirds the length, disposed in 

 more or less regular oblique transverse rows, at an angle of about forty-five 

 degrees to the axis of the branch, separated by about one-third the width 

 of an aperture. Peristomes obsolete. Interapertural space elevated, angu- 

 lated, enclosing the apertures in a rhomboidal or polygonal area. The crest 

 of the elevation is marked by a row of very minute granules and at the 

 angles by a more prominent node. 



