610 
APPENDIX A. (LONSDALE ON CORALS.) 
zone (fig. c), ■without, apparently, any of the intersections or subdivisions at the base mentioned in the 
description of Lithost. mammillare. The plates sometimes extended to the wall of the column in a single 
curve, but more often there was an intermingling of minor arches. The under surface exhibited no regular 
furrows or flattened ribs, I he laminae, which traversed the upper surface, were prolongations of the 
lamellae of the inner zone. In some cases they filled up, in a vertical section, the whole area of the 
bladder-like spaces, hut more frequently their dimensions were limited to a series of fine crests or la- 
mellae edges. Similar structures occur in British Lithost. fioriforme. 
The terminal stars not rarely exhibited a pseudo-proliferous character, in consequence of the uppermost 
series of arched plates having been in part accidentally removed or not fully developed (fig. a). This cha- 
racter was also sometimes strengthened by the irregular depressions or interspaces between the columns 
before alluded to. 
Cases of what were believed to be young columns, which had arisen from germs developed within the 
area of others, were noticed ; but the great irregularities in the grouping of the former lead to the infer- 
ence, that they frequently originated in an extension of the polypes over intervals due to unequal growth 
or accident. An instance was observed of three small columns, and part of a side of an old one, united in 
the middle by a thin triangular layer, which, on account of the arrangement of the rugose lines of depo- 
sition, had clearly resulted from the labours of three of the polypes. With respect to this assigned mode 
of production, it is necessary to state, that in the many English specimens of Lithost. fioriforme examined 
by the describer, not an instance occurred of a mature column totally studded over by young columns, 
and consequently of a parent smothered by its own progeny, though such appears to have been the case in 
some species of Cyathophyllum. On the contrary, the incipient columns always appeared near the inner 
margin, and thus left ample space for the upward growth of the old polype. Examples may possibly be 
discovered of terminal stars entirely occupied by the bases of small columns, but it is presumed that the 
extremities of the latter will be found to rest on the component structures of the old star, and not to 
spring from within them; and, consequently, that the superimposed columns originated in partial ex- 
tensions over a prematurely destroyed polype. 
Locality and Formation. — Borovitcbi, near Valdai. Carboniferous limestone. 
Favosites alveolaris, Goldfuss. 
Calamopora alveolaris, Goldf. Petref. p. 77. pi. 26. fig. 1. Favosites, Corrigenda, p. 245. 1826-1833. 
Favosites alveolaris, De Blainville, Man. d’Actinologie, p. 402. 1830-1834. Silurian System, part ii. 
p. 681 ; pi. 15 bis. figs. 1, 2. 1839. 
In Mr. Murchison’s Isle of Dago collection, was a cylindrical specimen of this coral, eighteen inches in 
length and five in its greatest diameter. It differed in none of its structural details from M. Goldfuss's 
excellent figures, except that the average width of the tubes at the outer surface of the specimen was 
rather less than a line, or about one-half of that of the unmagnified figure (1 a) in the Petrefacta (pi. 26), 
but the dimensions agreed very nearly with those of the fossil given in Mr. Murchison’s ‘ Silurian System’ 
(pi. 15 bis. fig. 2). There was, however, a difference, in an apparent total absence of the papillae on 
the inner walls of the columns, represented by Professor Goldfuss. 
Localities and Formation . — Isle of Dago, Petropavlosk and Volshanka River (North Ural). Upper 
Silurian. 
Favosites polymorpha, Goldfuss. 
Cal. polymorpha, Goldf., pi. 27 and28,pp. 79, 245 ; Silurian System, partii. p. 684. pi. 15. fig. 2. 1839. 
In the notice on this species in Mr. Murchison’s work, all the Favosites consisting of cylindrical 
branches, and wanting the peculiar vertical ridge within the tube, characteristic of the fossil figured under 
