24 BRYOZOAN FAUNA OF THE ROCHESTER SHALE. 
Fistulipora crustula n. sp. or new name. 
PI. VII, figs. 7-10; PI. VIII, figs. 16, 17; PI. XXIII, fig. 15. 
Compare Ceramopora incrustans Hall, Nat. Hist. New York, Pal. II, 18.52, p. 169, pi. 40E, figs. 2a-d; Gra- 
bau, Bull. New York State Mus., No. 45, 1901, p. 163, fig. 59. 
Zoarium incrusting, usually consisting of a single layer and this seldom more than 1 mm. 
in thickness. Surface marked with conspicuous maculae, which are sometimes elevated, hut 
more often depressed below the plane of the zooecial aperture. Measured from center to 
center the macular are on an average 3.5 mm. apart. Zooecial apertures 6 to 7 in 2 mm., 
arranged in more or less regular series radiating from the maculae. When the zoarium is in 
the youthful condition or the surface is worn, the zooecial apertures are somewhat rounded or 
trilobate and are separated by mesopores; but in the perfect mature stage the zooecial inter- 
spaces are occupied by walls or ridges, which, coalescing, form a polygonal area inclosing 
the aperture. Lunar i a small, but well developed, appearing as a crescentic elevation at one 
of the angles and projecting slightly into the zooecial cavity. 
In thin sections the zooccia are seen to be at first prostrate and then to bend almost at 
right angles direct to the surface. Interzocecial spaces occupied by a considerable number of 
large angular vesicles, the maculae also being simply clusters of vesicles. 
The incrusting growth, well-marked maculae, size of zocecia, small sharply defined crescen- 
tic lunaria, and the inclusion of tin 1 apertures in polygonal areas are particularly character- 
istic of this species. In all probability the latter feature would cause this form to be regarded 
as a species of Selenopora Hall,« the distinguishing feature of t his genus being the situation of 
the apert tires in a polygonal area formed by coalescing ridges. Inasmuch as this peculiarity 
has been observed in other genera, notably Ceramoporella, the writer has deferred the refer- 
ence of this and similar forms to Sdenopora until a thorough study of the entire group can be 
undertaken. 
The types of Ceramopora incrustans could not be found, but, judging from Hall's figures, 
that species and the one here described are apparently the same. The new name Fistulipora 
crustula is here proposed in the event of the two proving to be the same, the specific name 
incrustans having been applied to a European Carboniferous Fistulipora, first described by 
Phillips as Calamopora incrustans. Should Hall's types be found and differ from the speci- 
mens of F. crustula here described, both names will stand, unless of course Ceramopom 
incrustans proves to be a true Fistulipora, when another new name will become necessary. 
Occurrence. — Abundant in the Rochester shale at Lockport, Niagara Gorge, and Roches- 
ter, N. Y., and at Grimsby, Ontario. 
Catalogue numbers, 35481,35482, 35483, 35556, U. S. National Museum. 
Genus CHILOTRYPA Ulrich. 
Small ramose Fistuliporidn with a narrow irregularly contracting and expanding axial 
tube. 
Chilotrypa ostiolata (Hall). 
PI. VIII, figs II 15; PI. IX, figs. 1-1. 
Trematopora ostiolata Flail, Nat. Hist. New York, Pal. II, 1S52, p. 152, pi. 40A, figs. 5a-m. 
Chilotrypa ostiolata Ulricb, Jour. Cincinnati Soc. Nat. Hist., VII, 1XX4, pi. ;?, figs. 7, 7a. 
Chilotrypa ostiolata C.rabau, Bull. New York State Mus., No. 45, 1901, p. 164, fig 60. 
Trematopora coalescens Hall, Nat. Hist. New York, Pa!. II, 1852, p. 150, pi. 40A, figs. 2a, 1>. 
Chilotrypa'. coalescens Nickies and Barsler, Dull. U. S. Geol. Survey No. 173, p. 207. 
This is probably the most abundant bryozoan of the Rochester shale, fragments being 
found in great numbers wherever the bryozoan beds are exposed. Often several inches or 
more of strata are composed almost entirely of fragments of this species. Hall and Ulrich 
have amply illustrated and described the species, but for the sake of completeness, and in 
order to give measurements, the following description is offered: 
a Nat. Hist. New York, Pal. VI, 1889, p. xvii. 
