32 BRYOZOAN FAUNA OF THE ROCHESTER SHALE. 
like that of the zooecia, and appear as mere openings between the zooecia. However, 
sections through the mature region of aged specimens (see PI. XII, fig. 13), in addition to 
rather numerous small, granular, knotty acanthopores, show thick walls encircling both 
zooecia and mesopores. 
The zoarial growth of this interesting species is precisely the same as that pertaining 
to the highly characteristic Trenton bryozoan Eridotrypa briareus (Nicholson). a Internally 
the two species are also similar, but the slightly larger zooecia and larger and more numerous 
acanthopores of the Niagaran species will serve to distinguish them. 
Occurence. — A dozen or more specimens were found at Lockport, Niagara Falls, and 
Lewiston, N. Y., Grimsby and Thorold, Ontario. 
Catalogue numbers, 35518, 35519, 35520, U. S. National Museum. 
Eridotrypa striata (Hall). 
PI. XII. figs. 4-6; PI. XXIV, figs. 3-6; PL XXV, fig. 14. 
Trrmatopora striata Hall. Nat. Hist. New York, Pal. II, 1852, p. 153, pi. 40, fig. 7a-d. 
Trrmatopora ? striata Grabau, Bull. New York State Mus., No. 45, 1901, p. 167, fig. 66. 
The specimens described and figured by Hall as Trematopora striata prove upon exaun 
nation to be the basal portions of a species of Eridotrypa found rather frequently in the 
Rochester shale. 
As usual in basal expansions or on old examples overgrown by a layer of young zooecia 
tubes, the zooecia of this as well as other species of Eridotrypa are oblique and drawn out 
anteriorly. This seems to be a more permanent character in E. striata than in other species, 
and suggested the specific name. 
The base of E. striata is seldom found, the more abundant specimens being fragments 
of the slender branching zoarium. The specimen figured on PI. XXV is typical and shows 
the character <>f t he species. 
Internally E. striata differs little from the typical species of the genus. Indeed, in all 
features this Niagaran form is very close to the Ordovician species E. rnutabilis. Compared 
with associated bryozoa, E. striata resembles E. spinosa, but the smaller zoarium, smaller 
zooecia (6 in 2 mm.), and the few small acanthopores of the former will serve to distinguish 
the two forms. 
Occurrence. — Common in the Rochester shale at Lockport, Niagara Falls, and Rochester, 
\. Y., and at Grimsby, Ontario. Also rather abundant in the Osgood beds at Osgood, Ind. 
Catalogue numbers, 3551"). 14132, U. S. National Museum. 
Genus LIOCLEMA Ulrich. 
Although this genus reached its highest development specifically in later rocks, the 
Rochester shale affords a good representation. Individuals of the various species found 
here occur usually quite frequently, L. asperum and L. multiporum being particularly 
abundant, L. ramulosum being not uncommon among the small ramose forms, and L. e.rpla- 
natum and L. circinetum occurring least often. Some of these have a wide geographical 
distribution, the three first mentioned occurring also in Indiana. 
LlOCLEMA ASPERUM (Hall). 
PI. XI, figs. 1-3; PI. XXIV, figs. 14-16. 
Callopora aspera Hall, Nat. Hist. New York, Pal. II, 1852, p. 147, pi. 40, figs. 4a-i. 
Liocli ma asperum Ulrich, Gcol. Survey Illinois, VIII, 1890, pp. 416, 425. 
Lioclema aspera Grabau, Bull. New York State Mus., No. 45, 1901, p. 165, fig. 63. 
Zoarium incrusting foreign bodies, forming, by the superposition of several layers, rounc i 
or irregular masses, or, by growth upon ramose bryozoa or other cylindrical objects, roundec 
branches. Layers varying from 0.5 to 1.5 mm. in thickness; surface smooth, but, whei 
well preserved, hirsute from the abundance of acanthopores. Maculae of slightly large 
zooecia and more abundant mesopores but not a conspicuous feature. 
a Chxtetes briareus Nicholson, Geol. Survey Ohio, Pal., II, 1875, p. 202, PI. XXI, figs. 13-13b. 
