526 THE PALEONTOLOGY OF MINNESOTA. 
[Anolotichia. 
outer side in which very fine transverse lines may be noticed. Dimensions of 
zocecium of average size, about 0.3 by 0.4 mm. Interstitial cells varying greatly in 
size and distribution, some being very small, others as large and even larger than 
the zocecia. They form generally but a single series between the zocecia, yet it 
is not uncommon to notice a double row for a short distance. An obscure radial 
arrangement, with the zocecia in contact lengthwise, is noticeable about certain 
points, 6 mm. or more apart, where the interstitial cells are more numerous than 
elsewhere, without, however, at any time being in sufficient numbers to justify 
being called “ macule.” 
Vertical sections are even more characteristic, since in these the loose construc- 
tion mentioned is very striking. The zocecia appear as long irregular tubes crossed 
at variable intervals by exceedingly delicate horizontal diaphragms. The average 
distance between the diaphragms depends somewhat upon the horizon from which 
the specimen was collected. In zoaria from the lower and middle thirds of the 
Trenton shales, the average is between 0.5 and 0.9 mm., but in those from the Galena 
shales it is between 0.8 and 1.2mm. The interstitial cells assume all sorts of shapes, 
but are always extremely high. A tendency to arrange themselves in vertical series 
is usually manifest, but they cannot be said to form tabulated tubes, their walls 
being on the whole quite irregular and the end partitions more or less oblique and 
in many cases overlapping. All the walls have that peculiar granular structure 
noticed, in paleozoic Bryozoa, only among the Ceramoporide and Fistuliporide. 
Both the external and internal characters of this species are so distinctive that 
there is little or no danger of confusing it with associate massive forms. 
Formation and locality——Not rare in the three divisions of the Trenton shales at Minneapolis, St. 
Paul and Cannon Falls. It reappears, larger than ever, in the upper part of the Galena shales at several 
localities in Goodhue county, Minnesota, and at Decorah, Iowa. The original Manitoba type of the 
species I now believe to have come from strata equivalent to the last. It was collected at St. Andrews. 
Mus. Reg. Nos. 5963, 7602. 
Genus ANOLOTICHIA, Ulrich. 
Anolotichia, Ulrich, 1890. Geol. Sur. Il., vol. viii, pp. 381 and 473. 
Zoaria large, irregularly ramose or digitate. Zocecia comparatively large, form- 
ing long prismatic tubes, intersected by complete diaphragms more or less remotely 
situated. Walls thin, appearing transversely lineate in vertical sections. Apertures 
angular or subovate, direct, with a distinctly elevated lunarium. Thin sections show 
the lunarium to be traversed lengthwise by from two to seven minute, closely tabu- 
lated tubes. Mesopores very few in A. impolita, but moderately abundant, rather 
equally distributed among the zocecia, and of irregular form, in the type species. 
