BRYOZOA. 183 
Stictoporella.] 
The broad, maculose zoaria of S. frondifera are not likely to be confounded, although 
the two species are undoubtedly closely related. The following variety is good evi- 
dence of that. 
Formation and locality—Not uncommon in the lower third of the Trenton shales, at Minneapols, St. 
Paul, and several localities in Goodhue and Filmore counties, Minnesota. 
Mus. Reg. Nos. 5943. 7617. 
STICTOPORELLA ANGULARIS, Var. INTERMEDIA 2. Vr. 
PLATE XI, FIGS. 4, 5 and 7. 
This name is proposed provisionally for a form that is common at several locali- 
ties in Filmore county, but rare in the more northern exposures of the same beds. 
It differs from typical S. angularis, with which it is often associated, in forming wide, 
irregular branches, the growth and size being in many instances precisely as in the 
branching form of S. frondifera. At intervals the surface presents clusters of zocecia 
with thinner walls and larger apertures than usual. The mesopores are very few, in 
most cases restricted to the center of the clusters mentioned. Here they may form 
aggregations, but these are never, as far as observed, so extensive as in S. frondtfera 
One or two rows of them are also commonly present at the rounded margins of the 
branches. 
In having very few mesopores the variety agrees with S. angularis, while in its 
wide branches and general aspect it is like S. frondifera. The name intermedia 
alludes to its position between those species. 
Formation and locality.—Rare near the base of the Trenton shales, at Minneapolis, but common in 
the same beds near Fountain, Lanesboro and Preston, all localities in Minnesota; also at Decorah, Lowa 
Mus. Reg. Nos. 7597, 7599, 7984. 
STICTOPORELLA FRONDIFERA Ulrich. 
PLATE XI, FIGS. 12-19. 
Stictoporella frondifera ULRICH, {ss6. Fourteenth Ann. Rept. Geol. Nat. Hist. Surv. Minn., p. 72. 
Zoarium consisting of broad, irregularly branching, flabellate or undulate expan- 
sions, | or 2 mm. in thickness, the whole attaining a hight of from 50 to 100 mm. 
Edges rounded, with small pits (mesopores) in two or more rows. Surface with con- 
spicuous macule consisting of greater or lesser aggregations of mesopores, sometimes 
a hundred and more, generally about fifty or less. These macule are from 3 to 5 mm. 
apart, sometimes arranged in rows, but oftener their distribution is decidedly irregular. 
Between them the surface is occupied by the rounded zocecial apertures and meso- 
pores, the latter small and unequally distributed, varying in number from one, two, 
or even three to each of the former, Walls ridge-shaped, thick, usually nearly 
