Maryland Geological Survey 273 



Occurrence. — Helderberg Formation, Keyser Member. Keyser 

 (types), Cherry Run, West Virginia; Cumberland, Maryland. 

 Collection. — U. S. National Museum. 



Eridotrypa corticosa (Hall) 

 Plate L, Figs. 11, 12 



Trematopora (Chwtetcs) corticosa Hall, 1883, Kept. State Geol. N. Y. for the 



year 1882, pi. x, figs. 1-10; pi. xiii, fig. 4. 

 Trematopora ? (Trematella ?) corticosa Hall and Simpson, 1887, Pal. N. Y., 



vol. vi, p. 15, pi. X, figs. 1-10; pi. xiii, fig. 4; pi. xxiii, fig. 20. 



Description. — Zoarium solid, ramose, frequently branching, sometimes 

 at an angle of 90° ; diameter from -t to 5 mm. Zocecia thick-walled, polyg- 

 onal, G to 7 in 2 mm. At the surface the walls are strongly elevated and 

 sometimes coalesce, forming an irregiilar ridge. Mesopores few or want- 

 ing entirely. 



The polygonal zocecia with their- thick walls, will distinguish this from 

 other of the small associated ramose bryozoa. 



Abundant in the New Scotland limestone near Clarksville, New York. 



Occurrence. — Helderberg Formation', New Scotland Member. 

 North foot of Moore Knob, Washington County, Corriganville. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Genus LIOCLEMA Ulrich 



Lioclema subramosdm n. sp. 



Plate XLIII, Figs. 1-4; Plate XLIV, Fig. 5 



Description. — Zoarium subramose or irregularly ramose, the branches 

 sometimes intertwining to form thick clumps; the largest mass of this 

 kind seen, although incomplete, being 90 mm. in length and 50 mm. wide. 

 The free branches vary from 10 to 15 mm. in diameter. Surface smooth, 

 the maeulse, composed of slightly larger zocecia and mesopores, never rising 

 into tubercles or nodes, and being, on the whole, inconspicuous. Zocecia 

 6 to 7 in 2 mm., more or less polygonal, usually about two-thirds separated 

 by large, angular mesopores. The number of mesopores varies, the sur- 

 face of the same specimen sometimes showing them to be few and again 

 18 



