30 
one another alternately in opposite directions, successive corallites taking 
their rise from the base of the preceding calice. Tahulm sometimes present, 
at others absent, the visceral chambers connecting freely by their leases ; when 
jiresent, remote, delicate, and complete. Sej)ta representedhy delicate striae. 
Epitheca strong. Increase takes place by lateral budding. 
Obs. — “ These singular and beautiful corals,” says Prof. M‘Coy,^ “ have 
some relation to Anlopora, hut differ in their curious erect habit, regular, 
angular mode of hrancliing, slender, equal, stem-like tubes and abruptly- 
dilated terminal cups bent in nearly opposite directions. The Aulopores are 
attached for the most part by one side ; the tubes fjraduallij exj)and to the 
mouths, wliich all open nearly in one direction ; they have no regular distance 
for branching, and frequently anastomose. The present corals have also much 
thicker walls to tlie tubes, the central hollow being proportionally very small.” 
According to Prof. L. G. De Koninck,^ the tubes of the European 
Cladochonus MicJieUni communicate freely with one another. I have only 
examined a limited series of C. temiicollis, hut they are certainly similar in 
structure. Otlicr specimens, however, from the Carboniferous Limestone of 
Scotland, described by Prof. Nicholson and the Writer, and believed to he 
C. Mlclielini, were found to jiossess remote, delicate, and complete tabulae, 
cither straight or slightly curved. The relation of this genus to Aulopora 
has been summed up l)y Prof. Nicholson^ in the following vtords — “There is 
notliing in the internal structure of Cladoolionus, M‘Coy (= JPyrpia, Edw. 
& II.), which Avould separate it from Aulopora, Goldf., and the generic 
distinctness of the two can only rest upon the feature that the corallum of 
tlic former is erect, whereas in the latter it is creeping and parasitic.” 
Cladochonus tenuicollis, irCoy. 
C. tenuicollis , M'Coy, Auu. Mag. Nat. Hist., 1847, XX, p. 227, t. 11, f. 8. 
„ He Jvoninck, Hess. Pal. Xouv. Galies du Sud, 1877, Pt. 3, p. 154, t. 7, f. 2. 
„ Etheridge, .Tiuir., Cat. Australian Foss., 1878, p. 34. 
Sp. Char. — Corallum branching in the form of an irregular zigzag, hut 
more or less in the same plane. Calicos large, ohliquely-oval, cup-shaped, and 
terminal, united towards their bases by slender pipe or pedicle-like corallites, 
composed of a tliick homogeneous tissue, the internal connecting passage 
’ Ann. Mag. Nat. Hist., 1847, XX, p. 227. 
- Nouv. Reel). Anim. Fo.ss. Terr. Carb. Belg., 1S7'2, Pt. 1, p. 153. 
^ Tab. Corals Pal. Perioil, 1870, p. 223. 
