CORALS AND BRYOZOA. 203 



other at present known, except L. colliculata, and it may be distinguished from 

 that species by the somewhat larger cell apertures, greater prominence of the 

 features above mentioned, and the larger vesicles. 



Formation and localities. Hamilton group, Fall brook, four miles east of Can- 

 andaigua lake, and near York, Livingston county, N. Y. 



LiCHENALIA CORNUTA, n. Sp. 



KOT KIGDRBD. 



ZoARiUM consisting of explanate fronds, incrusting other objects, generally 

 Cy.athophylloid corals, having an observed thickness of about 1 mm. Cells 

 tubular, septa obsolete. Intercellular tissue composed of vesicles, which are 

 sometimes irregularly disposed, at other times regularly superimposed. Cell 

 apertures circular or trilobate, oblique, subimbricating, diameter .30 mm., 

 very closely disposed, radiating from the monticules and forming diagonally 

 intersecting lines, frequently in quincunx order. Peristomes thin, slightly 

 elevated, often scarcely perceptible, and having on one side a prominent 

 crescentiform projection, the extremities of which are prolonged into den- 

 ticulations, which in course of growth form two parallel striations along 

 the inner surface of the cell tube. Interapertural space slightly convex and 

 minutely granulose. Surface marked by monticules, the centers of which 

 are distant between 4 and 5 mm., arranged in sub-regular intersecting rows; 

 the center of the monticules are convex, minutely granulose, and destitute 

 of cell apertures for the space of 1.50 mm., the apertures immediately 

 adjacent are sometimes very slightly larger than those on other portions of 

 the frond. When the frond is worn or macerated, the interapertural space 

 is flattened, the granules are obsolete, leaving very minute, angular pits in 

 'their place ; in this condition it has but a slight resemblance to a perfectly 

 preserved frond. 



This species may be distinguished from Fistulipora constrida by the smaller 

 cell apertures, more prominent denticulations, and the granulose inter-apertural 

 space ; from F. ramosa by the manner of growth, being incrusting only, the 



