A8 PERMIAN FOSSILS. 
it may be said that in Acanthocladia the gemmuliferous vesicles are prominent, and 
situated on ridges which separate the rows of cellules ; whereas in Z/ammniscus they are 
cup-shaped cavities overlying the cellule-apertures. 
Mr. M‘Coy’s genus Jchthyorachis appears to be closely related to Acanthocladia in 
its mode of branching; but the arrangement of the cellule-apertures favours the idea 
of its reproductive character being similar to that of Zammniscus. 
All the known species of Acanthocladia are confined to the Palzeozoic formations. 
ACANTHOCLADIA ANCEPS, Schlotheim. Plate V, figs. 13, 14, 15, 16, 17, 18. 
KERATOPHYTES ANCEPS, Schl. Miinch. Akad., vol. vi, p. 20, pl. ii, fig. 7, 1820. 
— — »,  Petrefacten, p. 341, 1820. 
CERATOPHYLLITES — Schl. Boué, Edin. Phil. Journ., vol. xii, p. 144, 1825. 
GORGONIA — »  Goldfuss, Petref., p. 98, pl. xxxvi, fig. 1 a, 6, ¢, d, 
1828. (?) 
AN UNKNOWN Corat, Sedgwick. Trans. Geol. Soc. Lond., 2d series, vol. iu, pl. xii, 
fig. 7, 1829. 
GorGonta ancups, Sch. Germ. Transl. Geol. Man., p. 459, 1832; and 3d Eng. ed., 
p. 572, 1833. 
— — »» Phillips, Encye. Met., vol. vi, p. 615, 1834. 
— — »  Geinitz, Neues Jahrbuch, p. 541, 1841. 
a — ET G.puB1A, Schl. Morris, Catalogue, p. 38, 1843. 
— — »,  Geinitz, Geea von Sachsen, p. 98, 1843. 
FENESTELLA — » Bull. Soc. Géol. France, 2™ ser., vol. i, p. 24, 1844. 
—- — » Geol. Russia, vol. i, p. 221, 1845. 
a= — » Tennant, Strat. List Brit. Foss., p. 88, 1847. 
CERATOPHYTES — » King, Catalogue, p. 6, 1848. 
FENESTELLA — » Howse, T. N. F.C., vol. i, p. 261, 1848. 
_ — Et G. punta, Schl. Geinitz, Verstein., p. 18, pl. vii, figs. 19, 20, 22, 
1848. 
Diagnosis.—Stems numerous, erect, frequently dividing pinnately. Prnnules 
slightly tapering, generally opposite to each other, and blunted at their extremity. 
Rows of cellules from three to six on the stems. Cel/ule-apertures more or less circular, 
and somewhat apart. Capillary tubes slightly flexuous.' 
This Coral consists of a number of long, slender stems, rising from a small base 
round an imaginary axis, and giving off bilaterally, and at regular distances from each 
other, numerous branches, generally short and simple, but occasionally elongated, also 
bilaterally branched, and sometimes still further developed in the same way, assuming, 
in short, a bi- and even a tri-pinnatedform. The rows of cellules, separated from each 
other by a slightly-developed dividing ridge, are variable in number : generally there 
are only three ; but in some specimens so many as six may be counted. The vertical 
! The following is Goldfuss’s diagnosis: ‘‘ Gorgonia ramosissima, ramis subdichotomis, ramulis distichis 
brevibus, cortice osculis papillosis serialibus costata.”’ (Petrefacta Germaniz, vol. i, p. 98.) 
