CORALS AND BRYOZOA. 
199 
The elongate depressed maculae resemble those of L. alveata of the Upper 
Helderberg group, but the species may be distinguished as follows; the cell 
apertures are on a plane with the surface; the peristomes are equally elevated, 
are not denticulated and the apertures do not distinctly radiate from the maculae. 
The cell apertures, in form and size, very closely resemble those of L. ovata of 
the Upper Helderberg group, but it presents the following differences; the 
peristomes are equally elevated, are not denticulated, the maculae are narrow, 
elongate, depressed, the apertures nearest the maculae are not larger than the 
others, and sometimes do not radiate from them: from L. substellata it is dis¬ 
tinguished by the narrow elongate maculae, the obscure radiation of the aper¬ 
tures and equally elevated peristomes: from other species of this geological 
formation it is distinguished by the narrow, elongate-depressed maculae, uniform 
size of apertures and non-radiation from the maculae. 
Formation and localities. Hamilton group, shore of Canandaigua lake, Ontario 
county; York, Livingston county, aud four miles south of Le Hoy, Genesee 
county, N. Y. 
Lichenalia ramosa, n. sp. 
NOT FIGURED. 
Zoarium ramose, hollow, branches very frequent, diameter from 4 to 10 mm., 
thickness of frond from .50 to 2 mm.; the inner surface is a concentrically 
wrinkled epitheca. Cell tubes rectangular or oblique to the surface; septa 
very infrequent or entirely wanting. Intercellular space vesiculose; the 
vesicles are large and irregularly disposed near the base, they are smaller 
and more regularly superimposed above, but not having the appearance of 
walled, septate tubuli, from four to eight vesicles in the space of 1 mm , 
measured longitudinally. Cell apertures nearly circular, diameter .25 mm., 
irregularly disposed, generally separated by less than the diameter of an 
aperture and frequently in contact. Peristomes thin, scarcely elevated, and 
having on one side two slight denticulations. Interapertural space gently 
convex, granulose. Surface marked by circular, granulose maculee, destitute 
of cell apertures, the centres of which are distant about 3 mm., and their 
