INTRODUCTION. Ixv 
Family XIII. 
CYATHAXONID A. 
Corallum with well-developed, complete sepfa, which extend without interruption from 
the bottom to the top of the visceral chamber, and not forming a regular radiate circle ; 
those of the primary cyclum not much larger than the others, and not forming a four- 
branched cross, as in the Stauridz ; one well-characterised septal fossula. No dissepiments 
nor tabule. - 
Genus CYATHAXONIA. 
Michelin, Icon. Zooph., p. 258, 1846. 
Corallum simple. Calice deep. Colwmella styliform, strong, and very prominent. 
Septa extending to the columella; the place of one of them occupied by a deep depression 
or septal fossula. 
Typ. sp., Cyathaxonia cornu, Michelin, loc. cit., p. 258, pl. lix, fig. 9. 
Family XIV. 
CYATHOPHYLLID &. 
Corallum with incomplete septa, that do not extend from the bottom to the top of the 
visceral chamber, in the form of uninterrupted laminz ; those of the primary cyclum similar 
to the others, and not forming a central four-branched cross. Septal fossule: varying in 
number and in size. Visceral chamber divided by a series of superposed tabule. 
First Tribe—ZAPHRENTIN &. 
A single septal fossula, well developed, or replaced by a sulcus or a crestiform process, 
and occasioning more or less irregularity in the radiate arrangement of the septal apparatus. 
The corallum is simple, and free in all the known species. 
1. Genus ZAPHRENTIS. 
Rafinesque and Clifford, Ann. des Sciences physiques de Bruxelles, vol. v, p. 234, 1820; Caninia, 
Michelin, Dict. des Sc. Nat., Supplém., vol. i, p. 485; Siphonophyllia, Scouler, in M‘Coy’s Carbonif. Foss. 
of Ireland, p. 187, 1844. 
Corallum simple and trochoid. Calice deep. Septal fossula strongly developed, and 
occupying the place of one of the septa. No columella. Tabule moderately developed, 
and bearing on their upper surface a series of septa, which extend from the wall to the 
centre of the visceral chamber, and are denticulate all along their calicular edge. 
Typ. sp., Zaphrentis patula; Caninia patula, Michelin, Icon. Zooph., tab. lix, fig. 4. 4 
