278 
beds. Forms apparently identical to these occur in the lower Chazy of 
New York. 
Orbignyella nodosa, new species. is very abundant in the Lebanon lime- 
stone near Big Spring, Tennessee. 
Orbignyella sublamellosa Ulrich and Bassler, was first described from the 
Pierce beds near Murfreesboro, Tennessee, but further stratigraphic study 
of the Stones River group has shown that it is much more abundant and 
widely distributed in the Ridley limestone than any other species in that 
formation. 
RANGE AND DISTRIBUTION OF OTHER SPECIES OF THE STONES 
RIVER GROUP IN CENTRAL TENNESSEE. 
The table (page 310) is given to express briefly the relation of the 
Mollusea, ostracode sponge and coral faunas from the Central Basm region 
with the faunas of Stones River age from other localities and those of 
younger age found in Tennessee and elsewhere. 
DESCRIPTONS OF GENERA AND SPECIES 
ORDER CYCLOSTOMATA BUSK. 
The arangement of the zooecia. the form of the zoarium, and the presence 
or absence of interstitial cells and vesicular tissue are the important char- 
acters upon which the families and genera of this order is founded. 
The zooecia are simple and short, with minutely porous calcareous walls. 
Diaphragms are absent. The apertures are rounded, slightly raised, bent 
outward, and inoperculate. Ovicells are present. 
Family Ceramoporidae Ulrich. 
Members of this family may be identified by the more or less oblique 
aperture with an elevated lunarium often developed into a hood. The cell 
walls are minutely porous and composed of irregularly laminated and inti- 
mately connected tissue. Maculae of mesopores or of zooecia longer than the 
average occur at regular intervals. Diaphragms are few; mesopores are 
generally present, irregular and free from tabulation. 
Genus Ceramoporella Ulrich. Genotype: Ceramoporella distineta Ulrich. 
Ceramoporella Ulrich, Jour. Cincinnati Soc. Nat. Hist., 5, 1882, p. 156. 
Miller, N. A. Pal., 1889, p. 297. Ulrich, Geol. Surv. Illinois, 8, 1890, pp. 380, 
464; Geol. Minnesota, 3. 1893, p. 328. Procta, Syst. Sil. Centre Boheme, 8, 
pt. 1, 1894, p. 15. Ulvich, Zittel’s Textb. Pal. (Engl.,ed.), 1896, p. 267. 
Simpson, 14th Ann. Rep. State Geol. New York for 1894, 1897, p. 564. 
Nickles and Bassler, Bull. U. 8S. Geol. Sury., 173, 1900, p. 25. Bassler, ibid., 
292, 1906, p. 20. Grabau and Shimer, N. A. Index Fossils, 1, 1907, p. 121: 
Cunnings, 32d Rep. Dep. Geol. Nat. Res. Indiana, 1908, p. 742. Bassler, Bull. 
U. S. Nat. Mus., 77, 1911, p. 81; Zittel-Eastman Textb. Pal., 1913, p. 327. 
Zoarium consists of incrustations often superposed, forming masses, zo- 
oecial tubes are short and thin-walled, with apertures that are more or less 
