45 
1865-6. — In liis very remarkable paper on the “ Corals of the 
Palaeozoic Formations,” Mr. Rudolph Ludwig described and figured a small 
coral as Acanthoconium inversum, x which presents all the typical septal 
features of a turbinate form of Tryplasma. His very interesting figures 
re-illustrate, in a great measure, the very condition of preservation originally 
described by Lonsdale, i.e., an internal cast in which the longitudinal lines 
of the primary and secondary septal spines are represented by tube-holes 
penetrating the matrix ; the accurac}^ of his diagrammatic figure of the septal 
system is, however, open to question. At a later stage, in the same paper, 
the Author describes the cylindrical form, afterwards termed Tholidophyllum 
tubulatum by Lindstrom, as Tceniocyathus or Tceniolopas spinosa , 1 2 which is 
an excellent representation of a cylindrical Tryplasma — form, budding, 
septal-lamellae with spines, and tabulae. At least two species of Mr. Rudolph 
Ludwig’s genus Ttyc/iocyathus, 3 viz., P. profundus and P. granulifer, are 
referable to Tryplasma. The pore-like holes left by the dissolved-away 
septal spines are visible in the figures of both, and in the enlargement 
(Pig. le) of a portion of the weathered surface of P. profundus both the 
primary and secondary rows of septal spines are excellently represented. 
1870. — In this year Hr. G. Lindstrom 4 proposed his genus Pholido- 
phyllum , selecting as the type Cyathophyllum Loveni , M. Edw. and Haime, 
remarking — “ Its strange exotliecal covering in scaly rows, its septa, its well- 
developed tabulae, its double costie, and the complete want of dissepimental 
structure between the septa, justify my forming a new genus out of it, which 
I propose to name Pholidophyllum.” 
1873. — The genus Acanthodes was next proposed by Hr. W. N.Bybowski 5 
for the reception of several Silurian species, either simple or sub-fasciculate, 
provided with anchoring rootlets on the underside of the corallites, and narrow 
lamellar septa of two orders produced into spines along their free edges. 
The tabulae are variously formed, occupying the wTiole of the visceral space, 
but not reaching the wall, says Bybowski — a manifest error, although it will 
be remembered Lonsdale made the same remark ; no allusion is made to the 
presence of either a fossula, dissepiments, or exoinecal scales. Reproduction 
was observed only in one species (A. tubulus), the young corallites occasionally 
1 Ludwig — Palaeontographica, 1865, XIV, 4 Lief., p. 145, t. 32, f. 22a -e. 
* Ludwig — Palaeontographica, 1865, XIV, 5 Lief., pp. 187 and 201, t. 47, f. 3a-c, t. 57, f. 4. 
* Ludwig— Palaeontographica, 1866, XIV, 5 Lief., p. 196, t. 49, f. 1, la=e $ p. 196, t. 49, f. 4, 
4 Lindstrom — Ofvers. Vet. Akad. Forhandl., 1870, p. 925, f. n ; Geol, Mag., 1871, VIII, p, 125, f. 41, 
6 Dybowski— Mon. Zoantharia Scler. Rugosa, Pt. 1, 1873, p. 108. 
