293 



In tlio nialuro rojiiou tlioy nro much tliickoiiod, riiiR-liko, and soldoin in 

 contact DiapIua^^Mis arc few or wanlins,' in the axial porlion, hut more 

 abundant in the iieriplieral zone. Mesopoics are numerous or few, of irroK- 

 uhir shapes and sizes, and closed at tiie surface. Acanthopores are mostly 

 large and abundant with a conspicuous lumen. 



Ii(if(tstt,ni<i Jlhnna {t<affonl). Plate VIII, Figs. 5-7. tiUmopora libann 

 Safford, (Ji'ol. Tenn. ISOi), f). 2Sr». This species was described by Safford as 

 "like (S.) fibrosa, but with cell-tubes much larger." The following notes are 

 iiased on specimens and photographs furnished by the V. S. Nat Mas. and 

 sections of several specimens juM'sonally collected in Kutlierford County, 

 Tennessee. 



The zoarium consists of smooth, strong, irregularly arranged branches, 

 S to 12 mm. in diameter. ^laculae are present. 7 to s in one s(|. mm., dis- 

 tinguished by the larger size of the zooecia. 



In tangential sections the zooecia appear angular, thin-walled, nearly 

 everywhere in contact and i to 5 in 2 mm. A definite dark line separates 

 the walls of adjacent zooecia. Mesopores are few, and those i)reseid have 

 the appearance of young zooecia. Acanthopores are small, located at the 

 .junction angles, and less innnerous than the zooecia. 



In the longitudinal section the most striking featui-es are the scarcity of 

 diaphragms in the immature region, tiie narrow mature zone, and the 

 acute angle of approach of the zooecia to the surface following a decided 

 and short bend of the tubes fnnu the immature to the mature region. Dia- 

 Iilnagms 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 Central Teiniessee. 



Ilolotype : 44(;!>:! V. S. Nat. Mus. 



Paratypes : 247-2. .'*. 4 : 242-1. Imliana I'niversit.v. 



Batoxtoinit sKhciaxsiiiii //. .s/>. Plate IX, Figs. 1-."!. Zoarium is ramo.se, 

 subcylindrical <u- a little compressed, "» to 10 mm, in the greater diameter. 

 The surface is smooth with maculae (10 to 12 in one SQ. mm.) distinguished 

 liy clusters of large zoecia about an apparently solid area which consists 

 of mesopores, as shown in tangential sections. 



The zoecia in tlu' siu-face se(ti(ins are subangular. thick-walied. in con- 

 tact at nearly all sides and 4 to "» in 2 mm. Mesopores are small, few, sit- 

 uated mostly at the angles of contact of the macular zoecia. Acanthopores 

 are fmv, inconspicuous, and at the junction angles. The walls of contigu- 

 ous zoecia are st'iiai-ated by a distinct dark line in perfectly preserved sur- 

 faces. 



1)1 the axial region at the proximal tapering ends of the young zoecia the 



