INTRODUCTION The Devonian is represented along the Western Valley of Tennessee by highly fossiliferous formations of Helderbergian, Oriskanian, and Onondagan age. Unconformably overlying these strata is the widespread but nearly unfossiliferous Chattanooga shale, which is referred with some question to the late Devonian, but which may be of early Mississippian age. The stratigraphy and correlation of these Devonian formations have recently been discussed by the writer elsewhere.1 During the study of the faunas it was found that a number of characteristic indigenous forms are new to science, and these it is the purpose of the present paper to describe. There are thirty-seven new species, and three new genera. The accompanying synoptic table (page 114) will indicate the sequence and something of the character of the several Devonian formations. The Linden or Helderbergian group is here well developed, consisting mostly of limestone and calcareous shale, with a thickness of about 250 feet. Three breaks in this sequence separate the Helderbergian of Tennessee into four formations, but one finds it difficult to correlate these divisions in detail with the four divisions of the same group in the Appalachian trough. The reason for this is to be found in the fact that the Devonian of western Tennessee belongs to a southern or Gulf embayment. This epeiric sea was for the most part isolated and measurably independent of the Appalachian trough. In general, the Helderbergian seas were rather restricted in their spread except during the New Scotland epoch, when in many countries there was an expansion of the seas. At this time only, during the Helderbergian, is there clear evidence of direct communication between the Appalachian trough and the southern embayment which was covering western Tennessee; and the Birdsong shale fauna is then so nearly identical with that of the New Scotland of New York as to show not only exact equivalence in age, but also direct faunal inter-dispersions. Even at 'Stratigraphy and correlation of the Devonian of western Tennessee. Amer. Jour. Sci. (4), vol. 46, 1918, pp. 732-756. Published in more extended form as Bulletin 21 of the Tennessee Geological Survey, 1919. this time, however, the Tennessee faunas retained something of their provincial aspect, for certain highly characteristic forms, such as the Scyphocrini and Camarocrini among the crinoids and Rensselærina medioplicata, Eatonia tennesseensis, Gypidula multicostata and Meristella atoka among the brachiopods, did not spread into the Appalachian trough. Devonian formations having the same faunal facies as that of the Birdsong shale also occur along the Mississippi River in southwestern Illinois and adjacent parts of Missouri and again further to the west in the Arbuckle uplift of Oklahoma. These occurrences of Helderbergian strata serve to indicate something of the extent of this southern embayment, whose eastern shore flanked on the western side of the Nashville Dome and lay not far east of the present Western Valley, and whose northern limit extended some distance beyond Cairo, Illinois. The equivalence of the Birdsong shale and the New Scotland being evident, it would seem from the stratigraphic relations that the Rockhouse shale has its time equivalent in some part of the Keyser, and that the thick Olive Hill formation is of the age of the Coeymans, if not also of a part of the Keyser. As for the faunal evidence, the fauna of the Rockhouse shale is certainly of very early Devonian age, a fact that is indicated both by Silurian holdovers, as Dictyonella subgibbosa, and by the primitive aspect of such Devonian forms as Pleurodictyum trifoliatum. No faunal relations with the Keyser can be seen, however, for there was at this time no connection with the Appalachian basin. This small fauna has yielded eleven of the new species here described. The fauna of the Olive Hill formation is remarkable for the dominance of the Scyphocrini and their associated root-bulbs, the Camarocrini. These crinoids had previously appeared in Tennessee in the Decatur limestone of late Middle Silurian age. They recur in abundance in the Rockhouse shale, are at their climax in the Ross limestone member of the Olive Hill formation, and persist with a few stragglers through the Birdsong shale. They are also extremely abundant in the Helderbergian of Oklahoma. They are particularly characteristic of this southern embayment, where they must have been sequestered from Middle Silurian well into early Devonian time. During this period they appeared only sporadically in the Appalachian trough, several specimens of Camarocrinus having been found in the Manlius of New York, while these anchoring bulbs are common at one thin horizon in the Keyser of Maryland. In other respects, the fauna of the Olive Hill formation is largely made up of species which continue into the succeeding Birdsong formation, and the chief difference in these faunas is the sudden appearance in the Birdsong shale of many new species, the typical New Scotland facies, which now come to mingle with those already present in the Ross limestone. The Oriskany faunas of the Quall and Harriman formations again show an advent of the Appalachian faunas almost unchanged. The Camden chert, on the other hand, has a fauna distinctive of the southern embayment, which occupied practically the same position as that of Helderbergian time. It was only during the deposition of the almost immediately succeeding Pegram limestone that communication with the Appalachian seas was again established, and the Onondagan coral faunas attained western Tennessee. The evidence for the Onondagan age of the Camden chert is fully presented in the larger paper mentioned above. The study of these Devonian faunas was made in the paleontological laboratories at Yale University, and the types of the new species here described are the property of the Peabody Museum. The writer wishes to acknowledge his indebtedness to Professor Charles Schuchert for helpful criticism in the preparation of the paper. DESCRIPTION OF SPECIES CLASS ANTHOZOA FAMILY ZAPHRENTIDÆ Zaphrentis parsonsensis, n. sp. Plate I, figs. I, 2 Description: Corallite very large, simple, conical, straight, expanding uniformly and rapidly. Apical angle about 60°, so that the diameter of the calyx equals its height. Septa about 120 in number where the diameter of the calyx is 70 mm., alternating long and short. The type specimen is a natural cast which does not show the tabulæ, and they were probably not strongly developed. The length of the septa in the upper part of the cup is not shown, but in its basal portion the longer septa reach the center, where they are twisted into a pseudocolumella. Dimensions: Length, 90 mm.; diameter of calyx, 90 mm. Occurrence: A single specimen, the type, was found in the Harriman chert on Harriman Creek, near Parsons. SUBCLASS TABULATA FAMILY FAVOSITIDE Favosites foerstei, n. sp. Plate I, figs. 3, 4 Description: Corallum subhemispherical, the convex base covered with a thick and concentrically wrinkled epitheca which covers all but the youngest corallites. Upper surface, in the fossil condition, flat or concave. At the center of the base is a small point of attachment about which the corallum is symmetrically developed. The prismatic corallites arise from an undefined central axis and quickly bend outward into a horizontal position, which they maintain to the periphery. The corallites. vary in diameter from 1.5 mm. to 3.2 mm. at the surface, but the majority measure about 2.3 mm. Each side of a corallite bears two vertical rows of round mural pores, of which a row of ten |