293 
In the mature region they are much thickened, ring-like, and seldom in 
contact. Diaphragms are few or wanting in the axial portion, but more 
abundant in the peripheral zone. Mesopores are numerous or few, of irreg- 
ular shapes and sizes, and closed at the surface. Acanthopores are mostly 
large and abundant with a conspicuous lumen. 
Batostoma libana (Safford). Plate VIII, Figs. 5-7. Stenopora libana 
Safford, Geol. Tenn. 1869, p. 285. This species was described by Safford as 
“like (S.) fibrosa, but with cell-tubes much larger.” The following notes are 
based on specimens and photographs furnished by the U. S. Nat Mus. and 
sections of several specimens personally collected in Rutherford County, 
Tennessee. 
The zoarium consists of smooth, strong, irregularly arranged branches, 
8 to 12 mm. in diameter. Maculae are present, 7 to 8 in one sq. mm., dis- 
tinguished by the larger size of the zooecia. 
In tangential sections the zooecia appear angular, thin-walled, nearly 
everywhere in contact and 4 to 5 in 2 mm. A definite dark line separates 
the walls of adjacent zooecia. Mesopores are few, and those present have 
the appearance of young zooecia. Acanthopores are small, located at the 
junction angles, and less numerous than the zooecia. 
In the longitudinal section the most striking features are the scarcity of 
diaphragms in the immature region, the narrow mature zone, and the 
acute angle of approach of the zooecia to the surface following a decided 
and short bend of the tubes from the immature to the mature region. Dia- 
phragms are few in the peripheral zone, separated from one another by one- 
half to one tube diameter, and located near the abrupt bend of the zooecial 
tubes. They are rare or absent in the axial region. 
The less number of mesopores, the smooth zoarium, and the acute angle 
of approach of the zooecial tubes to the surface following the short bend 
from the immature to the mature region distinguish this species from B. 
magnopora in which the tubes proceed towards the surface in a very gentle 
curve until they enter the peripheral region. 
Occurrence: Lebanon limestone of Centrai Tennessee. 
Holotype; 44693 U.S. Nat. Mus. 
Paratypes: 247-2, 3,4; 242-1. Indiana University. 
Batostoma suberassum n. sp. Plate IX, Figs. 1-3. Zoarium is ramose, 
subeylindrical or a little compressed, 5 to 10 mm. in the greater diameter. 
The surface is smooth with maculae (10 to 12 in one sq. mm.) distinguished 
by clusters of large zoecia about an apparently solid area which consists 
of mesopores, as shown in tangential sections. 
The zoecia in the surface sections are subangular, thick-walied, in con- 
tact at nearly all sides and 4+ to 5 in 2 mm. Mesopores are small, few, sit- 
uated mostly at the angles of contact of the macular zoecia. Acanthopores 
are few, inconspicuous, and at the junction angles. The walls of contigu- 
ous zoecia are separated by a distinct dark line in perfectly preserved sur- 
faces. 
In the axial region at the proximal tapering ends of the young zoecia the 
