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diaphragms. Mesoposes are abundaut in the basal portion, decreasing in 
size and numbers in the peripheral region of mature specimens. They are 
closely tabulated and bead-like. Acanthopores are present, having a dis- 
tinet lucid center (lumen). 
Stromatotrypa lamellata n. sp. Plate XI, Figs. 1-2. The zoarium consist 
of superimposed layers varying from 1 to 2 mm. in thickness. The base is 
covered with a wrinkled epitheca. The surface is even and without dis- 
tinct maculae. 
The zoecia are large, 4 to 5 in 2 mm., irregular in size and shape. When 
the mesopores separate the zoecia completely, they are oval or subcireular, 
and where the mesopores are few or absent the zoecial tubes are elongate 
polygons as seen in the tangential section. 
From 8 to 7 acanthopores surround each zoecia and inflect the walls. 
They arise in the early mature zone, increase in size rapidly, and then taper 
gradually to their extremity which projects above the zodidal cavity in 
perfectly preserved specimens. 
The zooecial tubes are short and slightly inclined in the proximal region. 
The diaphragms are few, varying from .5 to 1 tube diameter apart. The 
mesopores are more numerous in the basal zone than in the mature portion 
and are crossed by relatively few and irregularly spaced diaphragms. 
This species differs from the laminated form in the Black River of Min- 
nesota in haying less number of mesopores with fewer diaphragms; more 
angular zoecia and pronounced inflection of the zoecial walls by the well 
developed and relatively thick-walled acanthopores. 
Occurrence: Pierce limestone, Murfreesboro, Tennessee. 
Holotype: 44718, U. 8S. Nat. Mus. 
Stromatotrypa incrustans n. sp. Plate XI, Figs. 3-4. Zarium forms thin 
inerustations (from .5 to 1 mm. in thickness) upon foreign bodies. The 
surface is smooth and without maculae. 
The zoecia are subangular, relatively thick-walled for the genus; 6 to 7 in 
2mm. Mesopores are few, occurring mostly atthe junction angles of the 
zoecial tubes. 
The acanthopores are about as numerous as the zoecia; of large size; 
thin dark wall, and a large central Incid area. They originate near the 
base of the zoarium and extend to the surface as well developed structures. 
In the zoecia there are three to four diaphragms, in the space of one tube 
diameter, and about twice that many in the mesopores. 
The smaller size and thicker walls of the zoecia, the less numbers of 
mesopores and larger and fewer acanthopores separate this species from 
Stromatotrypa lamellata n. sp. 
Occurrence: Pierce limestone, at ford 14, mile southeast of Blackman, 
Rutherford County, Tennessee. 
Holotype: 245—14. Indiana University. 
Stromatotrypa regularis n. sp. Plate XI, Figs. 5-6. The zoarium con- 
sists of thin layers upon foreign bodies, varying in thickness from .8 to 2 
mm. The surface is even, and without monticules or maculae. 
