90 PALAEONTOLOGY OF NEW YORK. 



STICTOPORA, Hall. 1847. 

 Stictopora Gilberti. 



PLATE XXVII, FIUS. '20-35 ; AND I'LATE XXVIII, KIGS. SI, 2i. 



Ptihtdietya {Stictopora) OilheHi, Mkkk. Pi-oc. Acad. Nat. Sci., Pliila. 1871. 



8tictopora OUberIi (Mbbk). Hall. Trans. Albany Institute, vol. x. ab.sti-act. \i. Vi. 1871. 



Hall. Report of State Geolojfist for 1882. Kxpl. pi. a."), tigs. 21, 22. 1883. 



Repoi-t of State Geologist for 1883, ailvanoe sheets. Expl. pi. 27, figs. 20-35. 

 188ti. 

 CytUidictya QUberli (Mbbk), Ulrich. .loumal Cincinnati Soc. Nat. Hist. Amer. Pal. Bi-yozoa. PI. 2, fig. 



5, no, 56. 1884. 



ZoARiUM consi.sting of a dichotomously branched frond, proceeding from a 

 spreading base; transverse section lenticular, abruptly contracting to the 

 margins ; width of branches from 4 to 6 mm. ; margins diverging ; greatest 

 thickness .75 mm., width of non-celluliferous margin slightly less than 1 

 mm. ; bifurcations occur at interv.als of from 5 to 10 mm. Cells tubular, 

 length from 1.50 to 1.75 mm., for about one-half their length essentially 

 parallel to the mesotheca, then turning abruptly outward. Cell apertures 

 oval, length about .25 mm., width from one-half to three-fourths the length ; 

 the margin.'il apertures slightly larger than those on other portions of the 

 frond ; disposed in longitudinal rows, which increase by interstitial addi- 

 tions. Hows separated by prominent ridges, which sometimes have a 

 depression along the middle. Peristomes strong, distinctly and equally 

 elevated, eiich one with a defined lunate process, the extremities presenting 

 two prominent denticulations, which in the course of growth form two parallel 

 ri<lges on the inner surface of the cell walls. The denticulations are invariably 

 situated on the outer margin of the aperture. Intercellular space irregularly 

 vesicular. 



This species may be distinguished from Stictopora incissurata, of the Hamil- 

 ton group, by its frequent bifurcations and the rapid increase in width of the 

 branches ; these characters and its larger size distinguish it from S. ovatipora ; 

 it differs from S. semistriata, by its more frequent bifurcations, strong 

 denticulations of the apertures, and more prominent continuous intercellular 

 ridges. 



