40 BRYOZOAN FAUNA OF THE ROCHESTER SHALE. 
Idiotrypa punctata (Hall). 
PL XVir, figs. 4-10; PL XXIV, figs. 17-19. 
Trematopora ?? punctata Hall, Nat. Hist. New York, Pal. II, 1852, p. 151, pi. 40A, figs. 4a-C. 
Idiotrypa parasitica Ulrich, Jour. Cincinnati Soc. Nat Hist., VI, 1883, p. 273, pi. 13, figs. 1-lc. 
Idiotrypa parasitica Simpson, Fourteenth Ann. Rept. State Geol. New York for the year 1894, 1897, p. 
591, figs. 187-189 
As indicated by the above synonymy, Ulrich's Idiotrypa parasitica is identical with Hall's 
Trematopora f? punctata. This fact could not be established with certainty by comparison 
with the published descriptions and figures of Mall's species, but a study of thin sections 
prepared from the original type of T. punctata, left no doubt in the writer's mind as to 
their identity. 
Mr." Ulrich has given a careful description of his species and the portion agreeing with 
the present view is reproduced below: 
Zoarium consisting of parasitic expansions, of variable thicknesses, usually attached to ramose 
bryozoa, but sometimes growing upon otner foreign bodies. The true zocecia have circular apertures, 
often closed by centrally perforated opercula, of an average diameter of one one hundred and twentieth 
of an inch, surrounded by a slightly elevated, thin, granulose, peristome. They are arranged with 
considerable regularity in scries, in which from eight to ten may be counted in the space of 0.1 of an 
inch. The intertubular spaces are of somewhal variable thickness, and usually appear to be solid: 
occasionally, however, the mouths of shallow interstitial depressions may be observed. The spiniform 
tubuli usually do not constitute a conspicuous external feature. 
Tangential sections show that the walls of I he t rue cells are marked by a dark circular band, equiv- 
alent to the peristome surrounding t he apertures. Within this band may be noticed, besides a limited 
number of rather thin-walled spiniform tubuli, a large number of smaller circular structures, usually 
provided like the spiniform tubuli, with a verj minute lucid central spot. These doubtless represent 
the granules above stated to occur on the peristome in well-preserved examples. The visceral cavities 
of all the cells appear to be more or less filled by sclerenchyma. This is due to the fact (shown in 
vertical sections) that the horizontal partitions are t bicker a1 t heir junction with the walls of the tidies 
than they are more centrallj . the cavities left be1 ween them 1 icing, t liercfore, of lenticular form. Some 
of the true zo ecia show a central, obscurely circumscribed area that may represent the openings of 
opercula of previous layers. These sections show further that whenever the horizontal partitions 
are broughl to lighi a large number of concent rically arranged dark or lucid spots may I e detected, 
which in the t rue cells gradually increase in size toward the circumference. 
Vertical sections, show that a very short immature /.one is present in which the zocecia} 
walls are thin and diaphragms practically wanting. With the inception of the mature 
/.one the mesopores develop, the wall of both zocecia and mesopores become greatly thick- 
ened, and diaphragms are inserted at frequent and equal intervals in each. 
Idiotrypa punctata is so different from all associated bryozoa that confusion with other 
species w ill hardly occur. 
Occurrence. — Not uncommon in the Rochester shale at Lockport, Rochester, and other 
New York localities. Less abundant in the Osgood beds at Osgood, Ind. 
Catalogue numbers, 35496, 35497, 43674, l\ S. National Museum. 
Family CALLOPOEIDJE Tlliicli. 
Genus CALLOPORA Hall. 
This is one of the best-characterized genera of trepostomatous bryozoa. Its species are 
usually represented by an abundance of specimens, and, having a wide distribution geo- 
graphically and a limited range geologically, are good horizon markers. The diagnostic 
characters of the genus are the ramose habit of growth, the rounded or angular zocecia 
and more or less numerous mesopores, the absence of acanthopores, and especially the 
method of tabulation. The mesopores are always closely tabulated, the zocecia less so, but 
have the diaphragms inserted in the following order: With the inception of a zoceciuin 
numerous diaphragms are developed and continue in the same abundance until the tube 
has reached the normal size; then in the rest of the axial region diaphragms are less com- 
mon, indeed sometimes almost wanting entirely, but when the peripheral zone is reached 
their number increases again. Compared with other genera the zocecia attain their normal 
