APPENDIX A. 
(LONSDALE ON CORALS.) 
617 
agreed with that of the Russian coral, the diameter of the central area was also about ten lines. The 
diaphragms were very thin, and undulated so far as they were exposed ; on one side were also indications 
of a siphon-like fold or sudden depression ; but this character was so indistinct, that if it had not been 
exhibited in other fossils, and described by the authorities alluded to in the remarks upon the genus, the 
fold or depression would not have claimed special attention. The margin of the upper or under surface 
of the diaphragms was likewise so defectively shown, that the inner terminations of the lamella: could not 
be detected, though in the Irish fossil they constitute a marked feature, forming a circle of bold sharp 
crenulations or narrow plates around the boundary of the area on the upper side of the diaphragm, and a 
series of grooves on the under side. 
2. The middle area or zone varied in width from four to three lines in different portions of the same 
transverse section, and in Can. (Siphon.) cylindrica similar inequalities were noticed ; but in the Irish spe- 
cimen, and possibly in the Russian, there was no constant connexion between the greater or less breadth 
and the position of the folds in the diaphragms. The lamellm were formed of two plates, distinctly sepa- 
rable, but the inner surfaces were exposed to a very limited extent. In vertical sections of the Irish coral 
this character is, in general, finely shown, the facility with which the two plates separate giving specimens 
of considerable length a great tendency to split. The persistence thus displayed in the vertical range of 
the lamellae, as well as the unbroken regularity of the highly inclined lines on their surface, exposed in 
one specimen from Ireland for more than two inches and a half, satisfactorily demonstrated that the same 
polype constructed the whole of that portion, though intersected by full fifty diaphragms ; and it is be- 
lieved that each specimen, even when twelve or fourteen or more inches in height, was the production of 
one animal. At the part, in the Russian fossil, where the siphon-like depression occurred, there was also 
irregularity in the arrangement of the lamellae. The union of the lamellae with the diaphragms could not 
be satisfactorily studied. The interstitial extensions of the latter plates between the lamella?, had, to the 
extent exposed, a nearly horizontal range, and they were slightly concave. 
3. The greatest width of the perfect outer area could not be ascertained, but it exceeded five lines : in 
Can. (Siphon.) cylindrica it varied in the same transverse section from four to seven lines. The inner 
boundary, as in that fossil, was well-defined by the abrupt commencement of the highly inclined, arched 
or vesicular lamina; of which the area was essentially composed. These lamime varied in form, position 
and extent, and they were occasionally furrowed and deeply indented, but no decided foramina were 
noticed, though they occur in the Irish coral. The attenuated extensions of the lamellae traversed the 
whole area so far as it was preserved, but not always in one uniformly persistent plate, instances occur- 
ring of splitting into subordinate ramifications, and their sides were always more or less feathered by the 
vesicular laminae. The structure of this area was also very imperfectly displayed. 
Locality and Formation. — East of Usolie, on the Volga above Samara. Carboniferous limestone. 
Caninia ibicina ? 
Conical, curved; central area, diaphragms connected marginally by bold extensions of lamella, siphon-fold 
small; middle area, inner surface of lamella-plates not readily separable, interstitial lamina horizontal, 
waved; outer area, vesicular plates numerous. (PI. A. fig. 6.) 
Turbinolia ibicina ?, Fischer de Waldheim, Oryctographie du Gouvernement de Moscou, p. 153. pi. 30. 
fig. 5 ; Miatchkova. 
Between the younger state, described in the next page, of this Caninia and M. Fischer de Waldheim’s 
Turb. ibicina, there is a considerable resemblance so far as the characters of the latter are delineated, both 
apparently consisting of a central area with transverse diaphragms, and an outer of vertical lamella; ; but 
it is difficult to imagine that the figure given in the ‘Oryctographie’ can represent a young specimen, and 
