44 PERMIAN FOSSILS. 
Genus Thamniscus, King, 1849. 
Diagnosis.—< The typical Thamniscidia. Stems frequently and irregularly bifur- 
cating more or less on one plane: celluliferous on the side overlooking the imaginary 
axis of the Coral. Cel/lules imbricated and arranged in quincunx. Gemmulvferous 
vesicles overlying the cellule-apertures.”! 
Type, Ceratophytes dubius, Schlotheim. 
I formerly placed the type of this genus in Lamouroux’s Hornera ; but it is evident 
from Mr. Lonsdale’s observations that this was an erroneous collocation.” At 
the time my ‘Catalogue’ was published, I had not made up my mind how this 
species, and the one following it, should be disposed of generically, though I felt 
persuaded that they could not be included in any of the reticulated genera then 
established. I was therefore induced to adopt provisionally the name which Schlotheim 
had given to them, under the erroneous impression, probably, that they were of a horny 
and flexible nature, and consequently true Ceratophytes as contradistinguished from the 
Lithophytes or calcareous Corals. 
The principal distinctive characters of Zhammniscus, compared with other allied 
genera, consist in the frequent and irregular terminal bifurcation of the stems, and in 
the gemmuliferous vesicles overlying the cellule-apertures. 
Probably the Fenestella intertexta of Captain Portlock,’ isa congeneric species. 
THAMNISCUS DUBIUS, Schlothem. Plate V, figs. 7, 8, 9, 10, 11, 12. 
ENCRINITES RAMOSUS, in pars, Schl. Minch. Akad., vol. vi, pp. 20-24, pl. u, fig. 4; 
pl. iv, figs. 16, 17, 1820. 
KERATOPHYTES DUBIUS, Schl. Petrefacten, p. 341, 1820. 
CERATOPHYTES — »  Boué, Edin. Phil. Journ., vol. xu, p. 144, 1825. 
GORGONIA DUBIA »  Goldfuss, Petref., pp. 18, 19, pl. vu, fig. 1 a, 6, ¢, 1826. 
Unknown Coratiine Bopy, Sedgwick. Trans. Geol. Soc. Lond., 2d series, vol. iii, pl. x1, 
fig. 5, 1829. 
GorGonta DuBIA, Schl. Germ. Transl. Geol. Man., p. 459, 1832. 
— — »  Quenstedt, Wiegmann’s Archiv, p. 91, 1835. 
— ANcEPS ET G, puBIA, Schl. Morris, Catalogue, p. 38, 1843. 
— DUBIA, »  Geinitz, Geea von Sachsen, p. 98, 1843. 
FrnEsTeLLA (Hornera 2?) ramosa, King. Bull. Soc. Géol. Fr., 2™ serie, vol. i, p. 23, 
1844. 
— (?) pusta, Schl. Idem, p. 24. 
—- 0? - » Geol. Russ., vol. i, p. 221, 1845. 
1 Annals and Magazine of Natural History, 2d series, vol. in, p. 389. 
2 Geology of Russia and the Ural Mountains, vol. 1, Appendix A, p. 628. 
* Report on the Geology of Londonderry, &c., p. 324, pl. xxii A, fig. 3 a, 6, ¢. 
