205 



ilividiiiii (>v('i-.v 1(» iiiiii. iiiln siilic.vliiHlric-il solid lirMiiclics. I lu C, in 



(li;iiti('(('i-. M.-iciiliic of cliislcis (if LirLjc /(icciii mtc r;itlici- imiiicrous. ("> in 

 (iiH'-l'ourth of 1 s(|. mill. 



Zoociii art' sul»iiii},'uiar. S In S'.j in ■_• i cniitiiiiions on I lie sides only and 



s('i)arat(Ml at most- an.ulcs liy intrrccilnlar spaces ( iiicsopnrcs i of in-e^rnlai- 

 siiajx's and sizes, in surlicial sections of mature siK^fimens. In taiijieiitlal 

 sections of tli(> siilMiiature ret;ioii or (d" youns specimens I he zoecia are 

 aiij^uiar and tliin-walled ; mesopores are few. 



Acanthopores are distinct, located at tlie junction aii.i,'les and lietween 

 contact zoecia. occasionally intlectinj,' the walls; 4 to 5 anionji 10 zoecia. 



In the longitudinal section the zoeciii of the axial region are thin-walled, 

 {•ros.sed by diapliraj,'ms. few in number, and arranged in zones, convex up- 

 ward, which probably bears a relation to periods of less rapid growth. The 

 zoecial tubes turn outward in a slight curve to the initial portion of the 

 thin mature region where the bending is short, angular and suttieient to per- 

 mit the zoecia to approach the surface i)eriM>ndicularly. The walls of the 

 zoecia on the mature zone thicken slightly and are separated by a distinct 

 miMlian dai-l< line. A single diai>hragm (alisent in some zoecia) is present 

 near the turn of the zoecia from the submature to the mature zone. 

 Occurrence: Pierce limestone. Murfreesboro, Tennessee. 

 Molotyjie: 44707 U. S. Xat. Mus. 



Hiitostaniii confcrta ii. .<</>. I'late X. Figs. l-."!. Zoarium consists of ramose 

 sulicylindrical solid stems ."> to (i mm. in diameter. Macidac and monticules 

 ai-e absent. Acanthoi)ores are large, sharply detined and irregularly dis- 

 tributed about the zoecia. Four to eight usually surround a single zoecium 

 and inflect one or all of the walls of contiguous tubes. 



In the tangential section the zoecia are thick-walled, polygonal, six to 

 six and one-half in 2 mm., with an occasional mesopore. There is a distinct 

 median dark line .separating the walls. In the axial region the zoacial tubes 

 are thin-walled. Diaphragms are rare or absent in immature region, but 

 numerous in the late submature region and in the mature zone; 3 to 5 

 occur in the space of one tube diameter. Incomplete and coalesced dia- 

 piiragms are rather abundant in each zoecial tube. 



( )ccurrence : IMerce limestone, Murfreesboro. Tennessee. 

 Ibdot.vpe: 4473U U. S. Xat. Mus. 

 I'aratype: 249-9. Indiana University. 



liiitoHtoma iiiutilis )i. .vp. Plate X. Figs. 4-."). Zoarium is smooth ramose 

 dividing dichotomously every C. to N mm. into compres.sed branches 4 to 5 

 mm. in greatest diameter. 



Zoercia are polygonal to circular. IVj to S in 2 mm. Mesopores are abun- 

 dant in some parts of the mature zone, .separating the zoecia completely, and 

 in other area, they occupy the .-ingular spaces (mly. The acanthoiKires are 

 of medium size, distinct and few, one among ten zoecia. They (iccasionally 

 inflect the zoecial walls. 



In the axial regitm. the walls of the zoecia are thin and wavy. Meso- 

 pores are absent and diaphragms are very rare. The tubes proceed to the 

 mature region in an undulating curve. A decided increase of curvature, the 



