596 
APPENDIX A. 
(LONSDALE ON CORALS.) 
The mode of developing tubes within the area of others was exhibited in every transverse and vertical 
section (fig. 9 a), but no satisfactory information was obtained, whereby their commencement could be con- 
nected with the production of the diaphragms, or separated from it. The polygonal form in these additional 
tubes was apparently produced by the gradual deposition of matter at the angles formed by the divisional 
plates with the walls from which they issued. In some few instances, a round pore, varying in diameter 
in different cases, was noticed in a thickened interval ; and it was considered to present a rudimentary 
state of an interspacetial tube, developed by an extension of the membrane connecting the polype mass. 
Localities and Formation . — Kaluga, and Vitegra, Borovitchi near Valdai. Carboniferous limestone. 
Chatetes dilatatus, Fischer. 
Incrusting ; lubes polygonal, small, short, vertical or inclined ; diaphragms not numerous ; superior termina- 
tion of tubes even, or tuberculated at the angles, and granulated on the edges. 
Chatetes dilatatus, Fischer de Waldheim, Oryc. do Moscou, p. 160. tab. 36. fig. 2. (Miatchkova). 
The coral believed to belong to this species, agreeing perfectly with M. Fischer’s description, en- 
crusted a specimen of Chat, radians. It occupied a surface about two inches in width and one in breadth ; 
but its greatest altitude did not exceed a quarter of an inch. It was distinguished from the species on 
which it rested, by the relative fineness of the tubes, the diameter being about one-fourth of a line ; and 
by their generally unconformable position, particularly in the lower portion. The diaphragms, so far as 
they could be ascertained, were irregularly distributed in this specimen ; but in another lossil, from 
Miatchkova, considered to belong to the species, they were very numerous ; and the membrane, men- 
tioned by M. Fischer as surrounding the mouth, appeared to be an imperfect development of diaphragms. 
In a sheltered position, a few preserved terminations exhibited a bold tubercle at the angles, and a series 
of finer points along the edges ; but no weight, as a specific distinction, is placed upon this character. 
Divisional plates connected with the production of additional tubes were noticed. 
Localities and Formation . — Borovitchi ; Miatchkova. Carboniferous limestone. 
Chatetes Petropolitanus. 
Globular, hemispherical or inversely conical ; tubes polygonal, irregularly arranged ; diaphragms not in bands 
but unequally distributed throughout the tubes. (Plate A., fig. 10.) 
Favosites Petropolitana, Pander, Beitriige zur Geognosie des Russischen Reiches, p. 100-105. tab. 1. 
figs. 6, 7, 8, 9, 10 a, 10 A, 11. 1830. 
Calamopora fibrosa, Eichwald, Systhme Silurien de l’Esthonie, p. 209. 1840. 
A careful examination of specimens agreeing with M. Pander’s figures and general remarks, led to the 
inference, that they possessed all the essential generic characters of Chsetetes. 
M. Pander considers the globular, hemispherical and conical specimens described by him, as varieties 
of one species ; and, it is believed, that the differences which may be noticed internally, depend on the 
conditions under which the polypidom was developed. In a well-preserved hemispherical specimen, 
two inches in diameter and nine lines in the thickest part, the tubes did not radiate suddenly from the 
centre, but the lateral increase had been produced by the successive addition of marginal tubes, which 
sprung from the base, and slightly inclined outwards. The concave under-surface of the same specimen 
exhibited, besides concentric irregularities, the oblique lower terminations of the tubes arranged in a manner 
which resembled radiating lines. In a conical specimen one and a quarter inch in height, and an inch 
in diameter at the upper (broad) extremity, the increase in width had also resulted from a similar mode 
of production ; but all the tubes necessarily raDged vertically, and the conical surface exhibited also circu- 
lar irregularities, as well as terminations of the tubes, though less distinctly in that specimen than in 
